Episodes
Wednesday Jul 31, 2019
Gerry Partida on Wrap Plating
Wednesday Jul 31, 2019
Wednesday Jul 31, 2019
Gerry Partida is back to talk to us about wrap plating and via filling and what the benefits, requirements and drawbacks of this technology are, and what you need to know about designing these and how this technology drives cost.
Show Highlights:
- Gerry is the Director of Engineering at Summit Interconnect with 35 years’ experience in the PCB industry, of which he spent 2 decades in boardshops.
- Were there indicators in your youth that you would end up in an engineering profession? Growing up NASA was in the middle of the Apolo program and being mesmerized by that was the beginning of it all.
- Definition of wrap plating: Wrap plating wraps copper onto the surface whenever we have a blind via or epoxy-filled hole, ensuring safe expansion and contraction during assembly.
- Benefits of wrap plating: saves real estate and protects via and with high-speed digital, it speeds up response times.
- IPC specs for wrap plating: IPC 6012 for rigid boards, 6013 for rigid-flex, and 6018 for RF. IPC4761, titled Design Guide for Protection of Printed Board Via Structures.
- The minimum wrap thickness at the knee of the hole changed recently - but the thicker the wrap, the harder it is to etch. Studies have shown that as long as you have some wrap, it’s reliable.
- By plating, epoxy-filling and plating over, we eliminate the chance of the solder going down a via next to a BGA pad.
- What are ‘butt joints’?
- Talk to your manufacturer about the optimum drill size and the requirements for epoxy-filling to prevent dimples or protrusions.
- If you have a blind via job, you must specify that they are to be filled and plated over.
- Gerry shows a hand tool that measures copper thickness around all the panels. It is used to verify, after planarizing, the lowest location and verify and cross-section to ensure that you are safe on thickness specs.
- A board shop will build in verification processes which take time - when you add epoxy-fill to a job, there are eight major manufacturing steps added to the job, which takes 24 hours in the quickest board shop. Basic board manufacture has approximately 26 to 28 steps.
- Make sure your fabricator does all the required steps for filling in-house.
- Minimizing wrap cycles creates greater consistency in your RF performance on an outer layer.
- Peel strength: when we epoxy-fill a hole it creates a smooth surface at the hole which weakens the peel strength.
- Thermal vias - conductive pastes do not conduct as much heat as copper - forget thermal paste, ask your manufacturer to plate 2mm of copper in the hole, just make the hole a bit bigger.
Links and Resources:
Wednesday Jul 10, 2019
PCB Design Certifications and Learning Programs
Wednesday Jul 10, 2019
Wednesday Jul 10, 2019
Today we’re going to talk about the importance of learning, as Eric Bogatin emphasized at last year’s AltiumLive. Please join my conversation with Ben Jordan where we explore a variety of ways that you can continue to learn and drive your career forward.
Show Highlights:
- A current hot topic on the forum is the value of CID or Certified Interconnect Designer Certification. This certification fills in many knowledge gaps not necessarily learned in college, such as the materials sciences and these classes are taught by gurus who started out as materials scientists.
- CID and CID+ are offered by IPC and are very useful by including how to present the results of your design to all the other stakeholders like testers, fabricators, and assembly.
- The IPC was floating the idea of recertification and it was not well received mainly due to the cost.
- Lack of practical experience is a barrier to job entry.
- Multi-disciplinary and systems-based thinking are terms we often see as criteria for finding jobs, not only the core technical skills.
- We would love to hear from our audience on whether a formal certification on a tool would help your career?
- IEEE has a recognition path called a Certified Professional Engineer which requires continual learning to maintain.
- The common thread from most industry experts is that continued and ongoing learning is crucial.
- The motivation for learning is the excitement of new technologies and most PCB Designers are very curious people by nature.
- PCB Design is never monotonous, every board is a new board.
- Robert Feranec will be a keynote speaker at the next AltiumLive; his curiosity drove him to research optimizing the hardware design flow in your company and he will be presenting his conclusions.
- AltiumLive is open to anybody, not just the Altium Designer user - pre-registration is now open.
- Keep your eye on our YouTube channels and our next Podcast.
Links and Resources:
Kelly Dack Podcast: What is PCB Design?
Circuit Assembly/UP Media article that raised the whole question on CID.
AltiumLive Summit 2019
Altium YouTube channel
Wednesday Jun 26, 2019
Board Fabrication Tips and Myths
Wednesday Jun 26, 2019
Wednesday Jun 26, 2019
Amit Bahl, the Director of Sales and Marketing at Sierra Circuits, is here today to discuss a more holistic view of not only board fabrication, but also assembly as Sierra Circuits does both. He’s going to teach you ways to think more about your total cost of ownership. We also do some fun myth busting around PCB fabrication and assembly.
To watch the video, click here.
Show Highlights:
- Amit says his story is pretty simple: he’s here to service PCB Designers, whatever they want or need, Sierra Circuits makes it happen and have been doing so for 30 years in Sunnyvale, California. Amit spent his high school years setting up drill machines and packaging circuit boards and got his training very early on. His father started the business in 1986.
- Their business is quick-turn and they do PCB fabrication, assembly, component procurement, all really quickly from a few buildings on Evelyn Avenue.
- Tips on looking at fab and assembly more holistically: The number one mistake is a failure to send boards in, in an array; customers tend to forget to send the array panelized drawings but Sierra takes care of that for their customers.
- What data do you really need upfront? Two types of data, first for the quote and also for manufacturing.
- For quotes: Gerber or ODB data or IPC 2581 data. Then there’s everything else for fab that has to be perfect: material, surface finish, any special requirements, PCB stackup; all detailed out in a fab drawing including impedance and dielectric control.
- It’s imperative to communicate with the fabricator and visit your board shop. It helps designers understand what happens on the floor, to see where variations can come in on different machinery and to design keeping in mind that each process is in a different department.
- Some myths surrounding fab and assembly. Websites are not always updated regularly, you cannot design based merely according to what’s on the website. Pick up the phone!
- PCB materials only hold up for a maximum of three to four laminations because of thermal stress.
- Don’t trust the data sheets, even for electrical properties - every material behaves differently. Isola 370HR is very reliable and consistent.
- Price and value are not equal - look at the total cost of ownership. Do you hire supply chain first and put pricing pressure on vendors, or are you hiring a quality department first and putting quality pressures on the vendors? Focus on quality and attention to detail is essential.
- Trust begins with relationships and with trust, specific aspects can be left to the fab house.
- Sierra will be at AltiumLive 2019, October 9 - 11 in San Diego, where face to face relationships can begin.
- Sierra is launching a Google Maps Street View for their facility, where designers can ‘walk through’ the shop virtually. This should be ready within the next three weeks.
- Trends: HDI, laser drilling, flex & rigid flex.
Links and Resources:
What is Design? Podcast with Kelly Dack
AltiumLive, San Diego, October 2019
Sierra Circuit’s HDI Design Guide
Tuesday Jun 18, 2019
Process Engineering for Advanced Assembly with Chao Vang and Sebastian Weber
Tuesday Jun 18, 2019
Tuesday Jun 18, 2019
Today we have a treat for you; we’re going to talk to two bright, young leaders at Advanced Assembly, Chao Vang, who’s the Engineering Manager there, and also Sebastian Weber who’s their Process Engineer. Both have come up through Advanced Assembly, learned in the trenches and they’re going to share great tips with you on how to make sure that your assembly is done right the first time and this will save you a lot of headaches.
Show Highlights:
- Chao’s degree and background are in Computer Engineering and Electronics Technology. She started off at Advanced Assembly ten years ago as the Coding Engineer; did sales for two years, and has been in her current role for two years now.
- Sebastian has a degree and background in Electronics Engineering and quick-turn assembly. He started as a Receiving & Shipping Supervisor and due to his technical knowledge, gradually got into more technical positions and eventually Process Engineer which he’s been doing for three-and-a-half years.
- Located in Aurora, Colorado, Advanced Assembly is the original quick-turn PCB assembly service shop; the pioneer in these services 15 years ago. Built from the ground up, they are specifically geared towards prototypes and small quantity quick-turns.
- Over the years they’ve assembled over 40 000 unique designs. With a staff complement of 105, their focus is that they are real people, with real experiences ensuring their customers get exactly what and when they need it.
- What happens after you receive the data package and files? Critical files required for DFA (design for assembly) check are: BOM, XYRS (pick and place files), and all the layers of Gerbers which must include copper, paste and silkscreen. For customers who don’t have all the files, we can create them.
- Most jobs (in fact, 95%, go on hold initially due to missing files.
- What is the first step for process engineering? Review files for special assembly notes, identify designs that aren’t necessarily the best for manufacturing and communicate on issues long before the actual build.
- What issues most routinely come up on the process engineering side? Via in pad especially on BGAs, glass top micro-BGAs, overage on very small parts.
- Common issues in front-end engineering: in the BOM, parts called out are not the same as in the description, for example, capacitors and resistors as well as polarity issues.
- How many parts on an average board? Between 250 to 500 - the DFA check takes almost two hours depending on complexity and some jobs have thousands of parts.
- What can your customers do to speed things up? Talk to the assembly house and ask what they need. A schematic and list of special requirements can help tremendously.
- Tips from engineering: Keep suggestions and feedback from the assembly house and do these implementations upon the next revision to avoid rework and related costs.
- How would customer’s implementing your suggestions impact you as an assembler? Mostly shorten lead time by preventing jobs from going on hold.
- Better planning means better results - partner up with your assembler and save money.
- All front-end engineering is done before a purchase order is even produced, meaning, the customer doesn’t pay for the DFA check.
- Parts sourced during the quoting phase through proprietary software and Octopart® shortens the sourcing time from an hour, to an average of 5 to 7 minutes!
- It’s been confirmed that Advanced Assembly will be at AltiumLive, October 9 - 11, 2019
Links and Resources:
Tuesday Jun 11, 2019
How to Conquer Data Package Problems
Tuesday Jun 11, 2019
Tuesday Jun 11, 2019
Today we meet with Rob Cooke, Director of Engineering, and Jose Cordero, Lead CAM Engineer from Calumet Electronics Corporation in Michigan. We talk about something that’s often overlooked, which is making sure your data package references the most current revision of IPC Standards. Listen in as we discuss slash-sheets, ENIG, and Via Plugging.
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Show Highlights:
- Jose jokes that nobody goes to college to end up in PCB fabrication. His background is in Art and Sound Design specifically. After completing his studies at Michigan Technical University he found Calumet Electronics, and the rest is history.
- Rob has been in the industry for almost 18 years, mostly doing design work in electronics for aircraft and military systems. He was appointed as the Director of Engineering at Calumet three months ago.
- From humble beginnings, Calumet Electronics has expanded to the point where today they produce between 600 and 800 panels a day, and over 3 million parts per year.
- The facility is unique in that it’s housed in a railway roundhouse - a very unique setting for a circuit board manufacturing factory.
- What are some of the things that slow down production due to insufficient data packages? A lot of confusion about IPC Material callouts.
- In 2017 there was a major update to IPC 4101 that changed the nominations of what materials are grouped under which category and materials are still being called out with the old specs.
- Designers need to pay more attention to their fabrication notes, and not reuse the same material callouts from previous designs. New spec updates are frequently missed, particularly in medical, aerospace and military parts where the design was produced five to ten years ago.
- Why are designers not aware of the update to IPC 4101? The pace of change can accelerate the development of the spec, and when IPC does make changes, it may not always be communicated well enough to end users.
- Via types: IPC 4761 describes seven primary types; some of the main ones are used interchangeably, even when that’s not the intent.
- Two main via types are type 5 and type 7 obviously selecting the correct type will influence both turnaround time and total board cost.
- Some folks try to specify some level of filled or capped via not using a spec but coming up with their own design notes.
- Things that throw us off: Materials instead of a class of materials are specified - there are many epoxies available. When a specific material is called for it could lead to extended wait times.
- We encourage defining plugged or capped vias by spec - the notes are ambiguous, vague, and cause the most problems.
- ENIG changes: There was a change in the spec this year. More gold is not better - the 4552 standard now has a maximum limit for gold, to prevent corrosion - whereas before there was only a minimum level.
- What is hyper corrosion and why it’s a problem: the gold is deposited on the nickel through a replacement process where each atom of gold replaces an atom of nickel - the more gold we add, the more nickel is removed, creating phosphorous molecules which is not a solderable surface.
- Designers need to verify on their drawings that specs haven’t changed.
- Ultimately the data pack is a way of communication between the designer and fabricator and it should be crystal clear. It’s also a critical point of reference for inspections.
Links and Resources:
Calumet Electronics Corporation
IPC Standards: IPC 4101 and 476, 4552
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Tuesday Jun 04, 2019
How to Buy PC Boards From a Board Shop
Tuesday Jun 04, 2019
Tuesday Jun 04, 2019
Today we talk with Greg Papandrew who’s just started a new company called Better Board Buying. With more than 27 year’s experience in PCB sales, he knows all the inside tricks to help you get the most out of your vendor partnerships and to save money and time.
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Show Highlights:
- Greg started in the industry as an inside sales and customer service guy. Believing he could provide a better service to his customers, he started The Bare Board Group in 2002, did that until 2013, and then ventured into consulting and helping customers acquire the best boards. His recent experience of the disconnect of buyers within the industry regarding their training led him to start his company to educate his customers in buying and to understand what they’re buying.
- What does Better Board Buying offer? Help buyers and engineers to buy boards better and what to look for. Improve the service that buyers are getting and help them realize that they can get better products and service - raise their expectations, most importantly bring back the personal touch. Better Board Buying offers a personal discussion about vendors, getting more buying power, taking care of all the hidden costs such as freight. Also, negotiating consignment stock and managing expectations.
- What has been lost since your start in the industry and today? I’ve been told my methods are ‘antiquated’ but they are, in fact, time tested. It does come down to relationships. The client’s confidence in the vendor to help them with any new job or problems, no matter the time of day, has been lost. Focus on the bottom line has negated the question, ‘what service are you getting for your dollar’?
- We have lost sight of the fact that the board is not just an item on a BOM that is bought on price only.
- Engineering and purchasing should collaborate more. Collaboration, inclusion, and buy-in from everyone is key.
- How should an engineer or designer think about a prototype and what does it mean to you to begin with the end in mind? First, determine the number of pieces, consider the purpose of the board, ask how it will be manufactured – a collaboration between design and manufacture is essential here – again relationships… Do you have corporate specs for PCBs to cut down on questions at the beginning?
- Why have we lost the cohesion and personal touch? The interest in manufacturing may not be what it used to. Perhaps procurement experience is not necessarily in PCB manufacturing and we lack that expertise.
- What are you personally doing to turn this thing around? LinkedIn articles, speaking at different conferences, word of mouth.
- What can people in procurement do to educate themselves? There’s plenty on the OnTrack Podcast, Circuits Assembly, PCB007, going to trade shows and talking to people there. It’s a skill you can acquire.
- What things in a board design can contribute to sticker shock once a board does go to production? There are many, but a few of importance: clarity on the finish, don’t over-design, cop away board thickness, how much routing or score is there (to save time), solder mask thickness, controlled impedance. Also, talk with your vendor, many board houses also have design engineers.
Links and Resources:
Greg LinkedIn
Greg’s article: Where have all the young PCB bloods gone?
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Tuesday May 28, 2019
Printed Circuit Fabrication Classes at Michigan Tech
Tuesday May 28, 2019
Tuesday May 28, 2019
In this episode we’re filming at Michigan Tech with guest Dr. Chris Middlebrook who teaches a class on Printed Circuit Fabrication. Watch or listen in on our first OnTrack Field Trip as we sit down in Dr. Middlebrook’s lab, where they make circuit boards right on campus. We talk about students, the education program at Michigan Tech and all the hands-on work they do to prepare Electrical Engineers for the real world.
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Show Highlights:
- Dr. Middlebrook has been a professor at MTU since 2007. At this engineering-focused university, they take a hands-on approach to help create engineers that are well-versed in practical design and implementation.
- What is MTU doing regarding the shortage of talent in the industry? The resurgence in manufacturing across all sectors calls for students being fully equipped and they strive to equip their students with the necessary skill set to drive the next generation of technology.
- Several lab spaces enable students to get hands-on with chemical and wet processes as well as prototyping and research, board etching and development. They work in small groups across campus.
- Calumet is very close to campus, they have been instrumental in the success at MTU, involving their engineers and scientists to get things up and running, they supplied much of the raw materials.
- Students eagerly sign up to tour the Calumet facility once they have experienced all the processes in class. Student feedback is very positive.
- Why is there a disconnect from the hands-on side of this work pervasive in most universities? Costs of materials and chemical sets is a primary factor. Not many students are interested in tinkering with things but that mindset is changing.
- What else can the industry do to support this initiative? Lab sponsorship, one concise, larger facility as a showpiece would make it more practical and create more opportunity for visibility to parents and students.
- More interaction and mentoring is something students respond to very well.
- Guest lectures pique student interest and broaden their experience across the spectrum.
- Topics covered in lectures: From electroplating within PCBs, to solder masks to assembly and multi-layer press to the future of this industry by Happy Holden.
- Positive elements of the Millennial culture: They’re very knowledgeable, already know where they are and where they want to be, they do a lot of things before getting to University.
Links and Resources:
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Tuesday May 21, 2019
Altium VP on New Library and Data Management Tool Concord Pro
Tuesday May 21, 2019
Tuesday May 21, 2019
Lawrence Romine, VP of Marketing for Altium, is here to discuss the release of Altium Concord Pro and it’s aim to provide a fresh approach to library and component management. Romine describes the modern, streamlined experience that reduces context switching, keeps communication in sync and enables an information flow that dramatically improves workflow, productivity and accuracy. We also talk about Altium Designer 19.1, what that includes and what you can expect from this performance-based release.
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Show Highlights:
- Lawrence started his career in electronics like most of us. His father was an EE and since the age of ten, he knew what he wanted to do - it was always engineering. His career of 20 years has evolved through the selling or business-end of engineering.
- He started in design with a particular interest in Audio at McCormick Audio from where he became involved in the semiconductor business working for Insight Electronics, selling and supporting Xilinx. In his search for more involvement with software, he joined Altium where he’s had a varied career over the last 15 years.
- What is Concord Pro? A library and component on-premise solution that works with Altium Designer and includes the MCAD collaboration capabilities which support Solidworks, PTC, Prio, and Autodesk Inventor.
- Concord Pro is very simple; it’s focused on library and component management to include an on-premise server.
- How is Concord Pro different to Vault, NEXUS and NEXUS Server? NEXUS Server is a rebrand of Vault, and the aim was for it to become a regulated ‘or gated’ design process. It made sense at the time to consolidate Vault under the NEXUS umbrella.
- Define the NEXUS ‘Channel’: NEXUS is a process-oriented solution, not a product, comprising configurable off-the-shelf modules; that Altium Configures and deploys on the customer’s premises with a joint agreement on the outcome - it’s applicable across the board; irrespective of the size of the company.
- A good example of successful deployment is in a smaller medical device manufacturer, which has a rigorous process to which they must adhere.
- Why was there a change from Vault to NEXUS? Customer surveys about library management confirmed that elements of NEXUS Server didn’t truly fit the profile of customers in the traditional Altium Designer Channel. Everyone has a need for reliable library and component management which considers supply chain information, ideally during the design phase but it doesn’t mean they need full lifecycle approval capabilities or to enforce any rigor in the design process itself, for example, gating of approval processes. These elements have been removed from Concord Pro, to make it more streamlined for the majority of users.
- What happens to Vault and Nexus Server users now? For current subscribers, it’s a free, painless move to Concord Pro. If you’re not using TC2 or the lifecycle approval process, all you need to do is update your existing product.
- For those that are using TC2 and lifecycle approval capabilities - just keep doing what you’re doing.
- Vault and Nexus will be maintained but not added to or sold individually going forward. Features will, however, be added to Concord pro.
- How does the ECAD-MCAD integration work? With Altium Concord Pro, we have a bi-directional push-pull arrangement with Concord Pro as the intermediary. So, you can make changes in one environment or the other, be it ECAD or MCAD - and the genesis of those designs can start in one domain or the other and push those changes into the other environment.
- As soon as an engineer emails a file, it’s no longer the most recent version, because they continue designing - check out the Concord Pro Page.
- What many engineers and designers are creating and calling a Bill of Materials is indeed a parts list. What Concord Pro brings to the table is enabling users to create a Bill of Materials as they go and this applies to everyone.
- Do take advantage of the 60-day evaluation offer on Concord Pro.
- Moving beyond Concord Pro, what’s on the horizon for Altium? We want to continue our aggressive growth and enhance the capabilities of our tool as our users are requesting.
- We are releasing Altium Designer 19.1 with a significant focus on engagement with the customer across the board where our customers congregate. There are significant investments in the stability and performance of the product.
- We listen to the customers and address what they tell us they need. We will continue to give our users a stake in the product and give them a voice.
- We are also looking towards the next 3D.
- What initiatives does Altium have in regards to raising the game on BugCrunch? We definitely listen to BugCrunch. We prioritize our action according to the number of votes received.
- We are paying attention, our developers are addressing a large number of issues daily. We will do more regarding responding or communicating to the users because a user’s perception is their reality.
- BugCrunch participation is not overwhelming; we need to inform users that it is their voice, and we need to do better with acknowledging and engaging the user.
- Shout out to Kelly in Salt Lake City - the largest Altium Designer user group, who are voting collectively to get their votes to the top of the priority list.
- What keeps you here personally? I’m still here because I chose this career path, business is about sales and marketing, which is ultimately about the narrative - the story - and this is a hell of a story. People are better off at the end of the process.
- We put out a solid product and we have a great ‘why’. We focus on the user first, we engage bottom-up and it’s working really well.
- Our sales process is unique - we believe that the user is the decision maker.
Links and Resources:
Podcast with John Watson
Concord Pro Page
Concord Pro Tutorials
Do Smaller Companies Need Data Management? Podcast
Altium BugCrunch
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Tuesday May 14, 2019
Dk And How Datasheets Impact Your Design
Tuesday May 14, 2019
Tuesday May 14, 2019
If you design in RF, microwave or millimeter wave frequencies today’s podcast is for you. Today we talk to John Coonrad who’s the Technical Marketing Manager for Rogers Corporation, a Global Manufacturer of advanced circuit materials. John talks about what dielectric constant (Dk) is exactly, the various test methods for Dk, why datasheets can sometimes be confusing and how all of this impacts your design.
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Show Highlights:
- John has been in the PCB industry for 32 years. His journey with Rogers began back in ‘87 when they had a division called FID (Flexible Interconnect Division) - he jokes that he was born and raised on flex circuits!
- For the past 11 years, John has been working specifically with the RF characterization of their materials as well as marketing and has been published in several trade magazines. John also chairs the IPC D24C Committee which defines high-frequency test methods for the industry.
- A working definition of Dk: The property of a material to sustain an electric charge by applying an electric GIL to it.
- In other words, dielectric constant is the ability to hold a charge and also to affect the electrical properties in regards to capacitance.
- On datasheets, the Dk can be inconsistent, which means that various manufacturers could provide different values because of how they’re testing which depends on what segment of the industry they’re serving.
- Rogers is unique because they choose to differentiate between Design Dk and Process Dk.
- Rogers performs a raw material test and does not test circuits.
- Using a clamp stripline test there is typically some trapped air, which has a lower dielectric constant and will cause a lower Dk overall.
- TIP: It’s helpful to check what test was performed when comparing datasheets.
- Currently, Rogers uses a test method specific to their in-house requirements which is process control as well as good QA test of the raw material, which is the Process Dk.
- Another test method is looking at how the Dk of the material is perceived in circuit form, i.e. testing microstrip transmission line circuits and extracting the behavior of the RF performance to get to the Dk of the material in circuit form - which is called Design Dk and provides a more realistic/real-world number.
- Bottom line: different test methods deliver different values.
- Other test methods out there: IPC has 15; the clamp stripline test is most common; full sheet resonance non-destructive test (FSR); split post dielectric resonance (SPDR), etc
- Because of the way electrical fields move through the dielectric, it’s not all about the traces, but the laminate has a massive impact, which is another reason why John’s work is so critical.
- As the chip industry evolves, there are more applications for millimeter wave frequencies - the higher the frequency the smaller the wavelength, making it more sensitive to any differences in material.
- With millimeter-wave frequencies, small differences in value can cause significant problems, especially in the automotive industry.
- Implications of incorrect Dk: Depending on the application, such as military guidance systems and base station equipment the Dk obviously has to be spot on.
- Pervasive misunderstandings that impact design engineers today: Not everything is taught in training institutions - for example, TCDk (temperature coefficient of the dielectric constant of the material) is often not accounted for. Circuit influences are also not accounted for but plated finish can affect the phase.
- How to learn about TCDK? Some sources: IEEE website; manufacturers of materials, and Rogers as well as John’s articles (see below).
- What’s driving more applications in the millimeter range? Designers and manufacturers of chips are now able to provide much higher frequency applications. The chips are being used for more varied applications.
- Is the increasing speed limiting PCB manufacturing? As you get to the higher frequencies, the features are very small and thus must be well-defined to avoid even little etching anomalies causing disruptions.
- What enabling technologies are emerging? For circuit fabrication, LDI is a definite plus. Regarding additives, some companies such as Averatek are doing excellent work and may be a potential solution.
- Thinner copper also enables fewer problems with surface waves. There’s also coupled circuit features.
- The line between chip design and board design could blur and we may adopt the precision and miniaturization.
Links and Resources:
Tech Hub
Rogers and Autonomous Driving
Rogers and 5G
Website Tools Page
Rogers ACS YouTube Page
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Read additional articles:
The Influence of Test Method Conductor Profile and Substrate Anisotropy on the Permittivity Values Required for Accurate Modeling of High Frequency Planar Circuits, read here.
Methods for Characterizing the Dielectric Constant of Microwave PCB Laminates, read here.
Read additional articles on the Microwave Journal:
Searching for a Standard Millimeter Wave Dk Test Method, read here.
Compare Materials in a Meaningful Way, read here.
Which Dk Value is Right for my Computer Simulation, read here.
Changing Temperature Can Change Circuit Performance, read here.
Tuesday May 07, 2019
Datasheet Reliability with Ben Jordan
Tuesday May 07, 2019
Tuesday May 07, 2019
When are datasheets accurate and can we rely on them? Ben Jordan is back on the show to discuss datasheets and how to achieve reliability for your use case. We also cover an unusual question from the forum about gilding that you won’t want to miss. Ben always enjoys catching up with the Lounge Forum, and this week, one of our users, Tim Philips, posted a datasheet that he had come across for an inductor. Listen in to explore these topics in this episode of the OnTrack Podcast.
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Show Highlights:
- The question: “I ran into an unusual datasheet from Murata, for a common mode choke and on page 7 it says: ‘Do not use a gilded pattern. The copper wire may cause open by dissolution of metalization’ - question is, what does ‘gilded’ mean?
- The answer: Gilded means gold plating - solder plated over hard gold just doesn’t work.
- This is a good example of how crazy datasheets can be, and it’s apparent that this was translated from another language.
- Lee Ritchey always says: “app notes, should be assumed wrong unless proven right”.
- This whole question of app notes and whether you can trust them is very important. For example application notes often advise separating the analog and the digital ground, to reduce electrical noise. Which is not necessary.
- Application notes are often produced by IC Engineers, who have no exposure to field theory and their conservative nature is aimed at the worst case scenario in various industries such as medical, aerospace and automotive where people’s lives are at stake.
- What’s the solution to unreliable datasheets?
- That’s where your training comes in. Starting with reference designs is good, but it’s just a starting point, you need to apply your engineering knowledge.
- You have to speak to applications engineers, who know products and did testing to compile the data–you have to verify.
- Measuring yourself, there are no shortcuts to actual measurement, you must have a test lab due to the ‘overkill’ of most sheets.
- Dan Beeker also says: “datasheets may be functional, but could result in higher BOM costs”.
Links and Resources:
Altium Lounge Forum
Rick Hartley on The Importance of PCB Stackup
Dan Beeker presentation "It’s all about the space"
Eric Bogatin: AltiumLive talk on measurement
OnTrack Email: ontrack@altium.com
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Tuesday Apr 30, 2019
Sourcing Components with Christopher Calvi
Tuesday Apr 30, 2019
Tuesday Apr 30, 2019
The Head of Octopart®, Chris Calvi is with us today to talk about sourcing components, which has never been more challenging than it is today. Chris will also share his vision of the future where sourcing components will be easy, accurate and fully transparent.
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Show Highlights:
- Chris attended Georgia Tech and after graduation he moved to LA, where he worked at Shopzilla, a consumer product search engine. He has 13 years’ experience in vertical search engines both in Business Development and General Management roles. He’s been with Octopart in New York for eight years, of which he’s served as GM for the last three years.
- Octopart was started in 2007 by three Physicists in Grad School. Due to problems with manually finding electronic parts in thick catalogs; the idea of a search engine was born.
- All three dropped out of school and thanks to Y Combinator program, Octopart got off the ground.
- Today there are between 800 and 900,000 users on the site monthly.
Octopart works with over 200 distributors who make it possible for the user to access the database for free. - The database gives access not only to the parts but also availability, validating, finding CAD models, symbols, footprints, 3D and exploration of technical details of each component.
- Part shortages is currently a huge problem especially with ceramic capacitors and LCCs.
- Octopart has a similar parts feature on the part detail page.
- The search criteria are very smart which is very helpful for everyday decisions.
- Availability and approved vendors lists as well as backup distributors are also available.
- Feedback is very positive regarding signals of risk and particularly lifecycle status.
End of life is a huge problem in applications such as aerospace and even on the repair side. - Octopart offers authorized channels or sources where the manufacturer has formal relationships with distributors. Octopart will have the authorized components come up first in your search.
- Compliance documentation and government regulations: there are restrictions on hazardous substances or chemicals - all part of the ‘problem set’ of selecting parts which Octopart strives to address.
- Vision and strategy for Octopart: First aim is a user-friendly solution. Second aim is for Octopart to be the go-to source for any relevant data on electronic components.
- Another aspiration is transparent structured data (information on where parts come from, last update, etc.) is essential for the future of electronic design and manufacturing.
- Machine learning and automated part selection applications means much more opportunity in the future.
- Obstacles now: Unstructured data, no data standards.
- CAD Tools and API: Application Programming Interface means you can tap into the database irrespective of what design tool you're using. This interface is another goal of Octopart and one that is receiving attention.
- For programmatic access to our electronic part search capabilities and part database, go to: Octopart API
- How are Altium and Octopart connected? Octopart serves as the parts enterprise unit for Altium. As Altium brings digital continuity; Octopart strives to bridge the gap as a structured data piece.
- Octopart is for everyone, not only Altium Designer® users, but also the makers, students, professional engineers, sources and procurement folks etc.
Links and Resources:
Octopart
Octopart API
Search parts by technical spec
Free ECAD models
Similar Parts (alternate parts)
Advertise with Octopart
Join the Octopart newsletter
Careers at Octopart
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Thursday Apr 25, 2019
What to Look for in a Board Fabricator with Steve Williams
Thursday Apr 25, 2019
Thursday Apr 25, 2019
Do you know what to look for in a new Printed Circuit Board Supplier? Today’s guest, Steve Williams, is the President of TRAC, also known as The Right Approach Consulting. Today he will share his tips, based on his visits to thousands of shops around the world, on what to look for in terms of certifications and how to look beyond the marketing and window dressing to source the ideal, reliable board supplier who will get the job done.
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Watch the video, click here.
Show Highlights:
- Steve started in the industry in 1976. He gained extensive experience as a Senior Manager in the board fabrication industry, followed by 15 years in QA, evaluating companies for best practices and technologies which proved how many companies out there needed help.
What to look for in a good board fabricator:
- Engineering Support: What kind of support do they have, how deep is their experience, and expertise? This combined with their people and the kind of software they use could save you a ton of money regarding materials selection in particular.
- Cleanliness: You can identify a good board shop by their FOD (foreign object degree) and what effort they make to keep it clean. Yes it’s a board shop but a dirty shop is an indicator of their culture and practices that affect performance and product quality.
- Dendritic growth is contamination on the surface of the board, that becomes encapsulated in the soldermask and will eventually galvanize the contamination leading to shorts from one trace or pad to another once the board goes under power, this is definitely something you do not want.
- Modern Equipment Sets: Are they keeping up with technology? If all of the equipment is old, it shows that their scope is very limited.
- Do they have Via fill, laser drills, planerizers, LDI, Inkjet printing, etc? This shows whether they’ll be able to support ongoing technology.
- Merit Badges; Such as QMS certifications, has become a first screening tool. Also, IPC training of employees signifies management’s commitment to quality; customers expect that. There should be trained IPC inspectors on staff.
- ISO Certification, must be part of the company culture, they need to be ready without prior notice for an audit. It should be a top-down culture within the company.
- Is the shop busy? Another indicator of future performance is how much activity there is. An empty is shop typically an indicator of something being out of place, even during economic down times.
- Speak to some of the employees, are they happy? You’re not going to get a good board from an unhappy employee, if the company can’t take care of their employees, how are they going to take care of their customers?
- IPC Validation Services is an excellent program. Most validated companies say that customers love it, and it’s been good for them, another priceless merit badge and a great differentiator.
Links and Resources:
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Tuesday Apr 16, 2019
EMC and Signal Integrity with Dan Beeker
Tuesday Apr 16, 2019
Tuesday Apr 16, 2019
Our guest today is Dan Beeker, Senior Principal Engineer at NXP Semiconductors, who is well known for addressing EMC and signal integrity in a really fresh way. Dan has presented twice as a Keynote Speaker at AltiumLive, both in San Diego and Munich. The information shared in this talk is extremely practical and valuable. Listen in, this information will impact the designs you do every day! Remember, it’s “all about the space”.
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Watch the video, click here.
Show Highlights:
- Dan started out with Air Force electronics training followed by his role as Motorola’s microsystems Group Test Repair Technician, and now Dan is the Senior Principal Engineer with NXP.
- You’ve presented twice at AltiumLive events as a keynote speaker, called “It’s all about the space” What does it mean, it’s all about the space?
The real key to successful engineering is the realisation that it is energy moving through space. It’s critical to design the spaces. The concept that the energy moves through wires, is what led us to where we are today. In the past where switching was very slow, it didn’t matter, however, as technology changed and switching sped up, we saw higher failure rates in EMC. - We reduced the size of the antenna required by an order of magnitude, practicing circuit theory without realising that energy moves through the laminate (the space). Energy also moves through the board space from one dielectric layer, up to a higher one.
- Why do you think engineers and designers alike lose this perspective along the way? It’s somewhat confusing, because geometry cannot be imported. Many still believe that the energy transfer is instantaneous. If that were the case there would never be signal integrity problems because energy transfer is much slower.
- This is also happening because the physics side of electronics engineering is made out to be something that’s quite difficult. There is a lack of cohesion between the science of energy and its reality and what we’re teaching people.
- The fundamental concept is we design products that generate, manage and consume electromagnetic field energy, not electrons. This field has to be in a space.
- Physics trumps theory!
- Five minutes into that class I knew that everything I had ever designed, had worked by accident! Rick (Hartley) became a friend and a wonderful mentor.
- Ralph Morrison taught me the importance of physics and that the energy was in the spaces and not the traces. He said: ‘People travel through the halls and not the walls, signals and energy travel in the spaces not the traces,’ which inspired my song.
- The geometry of the spaces has proven to be extremely successful with the help of my mentors.
- Finding great mentors is crucial.
- If you’re still in school, pay attention, take the extra time to talk to your professors and connect the dots of the behaviors of the electromagnetic field.
- Electronics is a world of three’s: You can store energy, you can move it or you can convert it into kinetic energy - that’s it, the entire electronics world!
- This is not an extremely complicated world for managing electromagnetic fields. You have three components: a conductor, a dielectric, and a switch. This isn’t rocket science, this is plumbing!
- You have to have to start using ground as a pointer object within your board stack. The common conductor from the source of the energy to the place where that energy is consumed, next to a common dielectric, so that the ground and the dielectric next to it, is unbroken from the source of the energy to the destination.
Technical conferences where you can see Dan Beeker speak:
- Embedded Systems, Boston in May
- PCB West in September
- Embedded Systems, Santa Clara this year
- NXP Connects in October, in Detroit
Links and Resources:
- It's all about the space song
- Ralph Morrison website
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Tuesday Apr 09, 2019
Design for Reliability with Yizhak Bot
Tuesday Apr 09, 2019
Tuesday Apr 09, 2019
Today we talk to Yizhak Bot who started his career in the Israeli DOD, and today he will share with us what derating is and how you can work on the schematic level with their simulation software to eliminate field failures. With a background including about ten years working with the reliability of very big systems gaining much insight into how systems work and fail, Yizhak is an expert you’ll want to listen in and learn from. Today he is the founder and CTO of BQR Reliable Engineering.
Show Highlights:
- Yizhak was a sponsor at both previous AltiumLive conferences and at the most recent, he spoke about the technology that BQR offers to engineers who lay out boards.
- A few common design errors that lead to field failures are: 1. Sudden CPU reboots, for example in aircraft - imagine an in-flight computer failure. 2. With safety- and non-safety functions together on one board, the non-safety functions will affect the safety functions - they need to be separated. 3. If you have a DC to DC converter - you’ll want to test if the voltage is correct and remember to connect them to the same ground, in the field it can be difficult to establish where the problem originates.
- What is derating as discussed at AltiumLive? You cannot use any component, current, or junction temperature running at its maximum rating; you must derate it.
- Integration, quality and field tests cannot find all failures that may occur because you cannot test all the combinations; using the simulation tool ensures your design is robust.
- Tell us about Fixstress and what inspired you to develop it? We wanted to find something to check for issues before products are in the field. We developed a tool that calculates stress levels of components, and a schematic review which detects design errors.
- Additionally, the simulation can do a thermal analysis and MTBF prediction to complete the analysis for the designer.
- What is the impact on your customers when using Fixstress? Almost zero failures in the field leading to the longevity of products.
- What kind of applications do you address and in which geographic regions? Mostly in big systems such as aerospace, also trains, automotive, shipping, telecoms, gas and oil, server farms, wind farms, power distribution. Our geographic market reach currently is the USA, Canada, Brazil, Europe, UK, Sweden and the Netherlands as well as China, Singapore, Japan and starting to work in Korea.
- Most of our growth is due to mouth-to-mouth referrals and clients asking sub-contractors to use the technology.
Links and Resources:
Tuesday Dec 18, 2018
Altium Designer 19: Highlights from the Latest Release with David Marrakchi
Tuesday Dec 18, 2018
Tuesday Dec 18, 2018
Altium Senior Technical Marketing Engineer, David Marrakchi is here on the show to talk about Altium Designer 19. This latest release is part two of three major releases Altium has planned to level up high-speed design capabilities. As an engineer who likes to wear multiple hats - and with experience in the field as an Electrical Engineer - David has done it all from developing requirements to schematic capture and PCB layout, across industries including home automation, military, and medical. Now he is bringing his rich skillset to the intersection of innovation and implementation by helping people understand Altium Designer and how to get the most out of the PCB design tools, easily and in the least amount of time. David is an inside expert on Altium Designer sharing his expertise on the overall processes of PCB design and product realization; playing a major role in creating product demonstrations, webinars, whiteboard videos, and interactive articles that illuminate the processes of printed circuit board manufacturing.
Watch the Podcast Video here and see more Altium Designer 19 videos.
Show Highlights:
Altium Designer 19 is released. David is hosting webinars to demonstrate new features. You can join live or on-demand--sign up for live webinars here: https://www.altium.com/webinars
What’s new in Altium Designer 19?
High Speed Design Features: What they are and how do they help designers?
- Advanced Layer Stack Management: Impedance solver, material library (vast array, pre-defined) and microvia support. Very important for tracks carrying high speed signals.
- Micro via (more info in the Interactive Routing webinar)
- Impedance modeling
- Material values - (there are always new materials coming out!)
New Part Search:
- Find a part that both meets requirements and that is also available!
- Search and filter with parametric information - global parametric supplier search. i.e. size, package, height, frequency, stock, model, and compare two parts.
Routing Improvement:
- New follow mode (allows for locking i.e. curves)
- HOTKEY / SHORTCUT: ctrl+f to lock to contour
Trace Glossing Improvements
Draftsman
Multiboard
Printed Electronics
Check out this Podcast with Tactotek to learn more.
Altium has a culture that embraces a mindset of continual “Relentless Innovation”
Some users say they’d rather us fix more bugs--why do we choose to continually innovate?
What value do you think this commitment to innovation provides to our users and the design community as a whole?
If you are an existing Altium Designer User you can download the latest version now at Altium.com.
If you are new to Altium Designer, we invite you to get behind the wheel and take it for a test drive and see why Altium has become the fastest growing PCB Design company in the world.
Links and Resources:
Wednesday Nov 21, 2018
Wednesday Nov 21, 2018
John Mitchell, CEO of IPC, is advocating for the electronics industry workforce in Washington D.C., and participating in the Pledge to America’s Workers. Listen in and learn how IPC has joined in pledging 1 million new job opportunities for the industry, when John shares a "state of the union" about IPC’s current direction.
If you’re a current IPC member, you’ll benefit by finding out all that IPC is up to these days and and how you can get involved. If you’re not an IPC member or not sure what IPC is - you will get a lot of value from this conversation just by learning about this incredible industry force and all that’s available, including educational programming and career development opportunities.
See the show notes and links to all the great IPC resources at: https://resources.altium.com/altium-podcast/john-mitchell-ceo-ipc-visits-the-white-house-pledge-to-americas-workers
Tuesday Oct 09, 2018
AltiumLive 2018 Panel Discussion
Tuesday Oct 09, 2018
Tuesday Oct 09, 2018
Tuesday Sep 25, 2018
Manufacturing Documentation with Duane Benson
Tuesday Sep 25, 2018
Tuesday Sep 25, 2018
Manufacturing documentation is crucial. Get pro tips from Duane Benson of Screaming Circuits on how to deliver the ideal manufacturing documentation package, so all the technical details are documented exactly as needed. Every fabrication and assembly house is different, so it pays to prepare in advance and find out what documentation to produce for your design to be manufactured. You don’t want to miss this week’s episode; it’s full of practical advice so you can navigate fabrication and assembly effectively and know what to expect in this very complicated process.
See all the show notes here.
Show Highlights:
- ActiveBom - use it! Excel is not the best tool for designing with.
- Traditionally a manufacturing house needs Gerber files. It’s a text file that creates a bit-map.
- More advanced/new way of doing this is with a single file, the most popular being is ODB++ (was proprietary, now public domain)
- What is Gerber X2? Allows you to put intelligent data on top of the Gerbers.
- Once you pick a fab or assembly provider, call and find out what files they prefer. It’s complicated to explain, so call your fabricator and assembly house.
- When you send multiple files, send the same versions. It’s really common to see different versions of files because small changes were made but not all the documentation was updated.
- IPC specifies pin location but so many of the footprints don’t follow the IPC standard.
- This is not a “no touch” process.
- If you need a fast turnaround, then be available 24/hours a day to provide answers and get back to manufacturer immediately. It’s a complex job, things happen.
Ideal Manufacturing Files:
- Everything is current and same version - everything checked
- Read me file - cover anything non-standard, covered clear and concise (include stackup)
- BoM in Excel format, possibly with substitutes
- Intelligent file formats i.e. ODB++
- If Gerbers, include Centroid file and certified that rotations are correct
Hey everyone this is Judy Warner with Altium's OnTrack Podcast thanks for joining again. You will see a familiar face on the screen next to me, but we have a great new topic to talk to you
about that I think you'll find very compelling. Before we get started you know, same old stuff.
Please subscribe to the podcast, please let us know your ideas for future topics, and also
follow us on social media. Of course, I would like to be connected to you on LinkedIn. On Twitter I'm @AltiumJudy and Altium can be found on all the usual social media channels. Something I
don't think I've mentioned before on the podcast is that I also edit the newsletter for Altium, and it also carries the OnTrack brand, so it's the OnTrack Newsletter. Duane Benson who is with me today - from Screaming Circuits, has actually been featured in that newsletter and you can find that at resources.altium.com and also in that area of our website, you can find just oodles
of information. So many, many blogs on subjects you can filter by topic and I think you'd really enjoy it. So again that's resources.altium.com, so jump in and enjoy that.
Well Duane Benson's back again from Screaming Circuits, we connected again recently and we were talking about the the kind of muddy waters of manufacturing files and formats and what it's like for someone like Duane to deal with a variety of issues that come up and so I thought, as
PCB designers, that you would like to learn some tips and tricks - kind of what some of the obstacles are - and get familiar with some language if you're not already, and then hear from an expert of what a manufacturer - what a really good design Manufacturing file package looks like. So Duane, welcome back.
Thank you, thank you for having me I had a lot of fun on the last podcast and you know I have weird, geeky interests, and manufacturing files is one of them, so anytime I get to talk about one of my weird geeky interests, I'm happy.
[laughter] Well I track with that weird geekiness of you, so I know we talked - preparing for
this podcast - it should have taken like 20 minutes; we just went off on a bunch of different topics but hopefully you'll enjoy the results of our geeky conversations. So let's start out with
just defining what you are characterizing as manufacturing files?
Well there isn't a real solid definition of what a manufacturing file set is, but if you think about an electronic design of some sort that starts with an idea in an engineer's head, and it becomes
schematics, it becomes a Bill of Material, it becomes Gerber files, layout files, things of that sort.
Essentially it's an electronic file set of everything that an engineer would feel would be needed to describe their product, and it's in a format that a company like us, an assembly house, and a
board house and part supplier, can read to turn that idea into a working board. So there's an awful lot of things that go into it. You have to describe the raw PC board, you have to describe the components, you have to describe the assembly, and anything special or unique about it. So the manufacturing file set is all of those things necessary for someone, who is not you, who is not in your head, to take your design and turn it into a working board. Well in the case of electronic manufacturing service I think kind of one of the central pieces that comes to mind for me is the Bill of Materials.
So you want to touch on that hot mess? [laughter]
The Bill of Materials really is a hot mess, it is one of the most important files. Unfortunately, this doesn't get the highest profile because it's not you know, the design. That's the bit that everything starts when we're building a board, everything really starts with the Bill of Material and that includes, a typical Bill of Material is again, that's what we need in order to communicate with the distributor to buy your parts, so it will have the manufacturers part number and every single character in that manufacturers part number is important. Some of these things are twenty characters but those little suffixes may determine the temperature grade or something like that, or how its marked, or how it's packaged all that's important as well as the manufacturers name. So you've got the manufacturers part number, the manufacturer's name, and in theory that should be enough. But we always like to be able to double-check things, we always like extras for quality control, so we would like the value of the component as well. So, if it's a 0.01 microfarad, 16 volt 0805 capacitor, we would like that, and then a package size. Again that's a double check, so if we get something that's not even close we can tell, hey that's not the right part. Then we also need the reference designator on the board, that's what tells us where the part goes on the board - the reference designator - and then a line item so that we can easily identify it. If we have to call the designer and say, you know hey this part doesn't fit, we can say it's line item six on the Bill of Materials.
So that was manufacturer, manufacturer's part number, the value, the reference designator, and a line item that we can use to identify it. Other things can go into the Bill of Material, but that's really the minimum set.
And I think, in my - at least, my experience in the past - and you can correct me here, because I'm not as adept as you are here. But I've seen Bill of Materials that are a little messy, and they only have part of the part number, so they just put in the part they know and then you're like, what do I do with this?
Yeah you know, a lot of Engineers have told us that they would love to be able to say, I just want 2.1 microfarad, 16 volt or greater cap, that's it and that's all fine and dandy if you know that, all those other parameters don't matter. A capacitor; it has the dielectric specifications, it has ESR or ISR specifications - you as the designer know if those things matter or don't. We as a manufacturer, don't know that they matter or not. If they don't matter, then sure it'd be awesome to be able to just pull some random capacitor, but we don't know that. So they need to know every single bit of that part number so we can get exactly what you want. That's a bit of a challenge, especially with capacitors and resistors these days, because of allocations - these things come and go out of stock so fast and, so anytime one of those parts is in the Bill of Material and it's out of stock, we've got to call up the engineer and ask for a substitution because again, we don't know if they need a high or a low ESR part and we've had cases where you know someone will send us a Bill of Material in the morning and if we go back to the distributor the next day, some of the parts are out of stock it's just absolutely crazy.
-Yeah.
What that says though, is the important thing is, when you create your Bill of Material, what you're doing over time as you put your design together, make sure that the very last thing you do before sending those files off to the manufacturer, is to verify that those parts are still in stock and if not, find a substitute that you know will work.
That's a good - that's a very good point being the last check. You had asked me a little bit
about a feature inside of Altium Designer called ActiveBOM, so I did a little checking with Ben Jordan about that and so what I learned about that is that it's an interactive BOM management
tool, that's inside the design and it has multiple output files. You can scrub it at any point in the design process kind of like you're saying, do it at the end, but you can do it throughout the design process, and it will tell you the ability to parts, it can help you find alternatives. When you change a part in design it changes the BOM…
-oh nice, I love it.
Nice right, I know, and then flags will appear, like if you're designing and something is at risk of going out of stock, or end-of-life or whatever, a flag will appear on the BOM that will tell you; we better go check this one out and see what's going on. So those flags come up also kind of in real-time throughout the design process so I think that's a really helpful tool and you know I think a lot of designers that are using our tool are jumping into that because I think it would be a
really valuable kind of aspect of our tool. But I know some haven't either, so I just wanted to jump in quick - if you are using Altium Designer and you're not using ActiveBOM, use it
because I think it's an invaluable tool.
Yeah a surprising number of people just use Excel and well, that's what we end up needing, we need an Excel file as the output, but it's not the best tool for designing with.
I know and it's kind of amazing that you know, we can create these little suckers and we're still
doing our BOMs on Excel spreadsheet but, there you have it.
So why don't you go over the type of outputs that are say from a CAD tool - like Altium Designer or any other, the type of outputs that you would typically see?
Okay and this is where the industry is really on the precipice of change, but we're still stuck in the old world. Traditionally, a manufacturer like us, and a board fab house would need a set of Gerber files - and most people know what Gerber files are - if they don't it is a file - a set of files - and there's one file in each set for each layer. So copper would have - top copper would have a file, it is a text file, but I like to describe it as a one bit depth bitmap because it's a text file that creates a bitmap. So you can't, you don't at the moment, have any intelligent information in there. A pad for a component looks exactly like a trace, looks exactly like a pore, so that is the way it's done today but it's not optimal, so you've got the Gerber file set again - one file for
each layer - so you'd output that from your CAD system and you'd put that into a zip file and that's what we would call the Gerber files. Within your CAD system, quite often people will have
an assembly instructions layer, or a fab notes layer, make sure you put those in the Gerber files also, because those are the only real opportunities to integrate information into that Gerber file.
Now if you're going to have the boards assembled, you'll also need something which may be called a centroid, that's what we call it, some people call it a pick and place file, and that has the XY location on the PC board of the component. It has the reference designator, again that's why we need reference designators, and it has the rotation of the component zero to the orientation and the top and bottom side. So Gerbers - with Gerbers you have to have that centroid, or pick and place file, otherwise we don't know where a component goes. That's the basic set and then we would also like something that would have notes that tell us the layer stack up you know, which layer goes where. That's really the minimal set. You also, if you have things like some people for example, don't want to put reference designators on their board and silkscreen. That's really a bad thing, but for aesthetic reasons people don't. Well, then you need a set of fab drawings that tells us where the reference designators are, so that would be another thing that you would need to go in there.
Also in the fab notes would be, if you have overhanging parts for example, these little tiny USB micro-b connectors hang over the edge of the board, and they've got a little tab that goes down. Well if you're having your boards panelized and it's either a v-score or tab routed panel, you can't do that, and build that part, so you have to specify in the fab drawings: don't put a panel tab here, things of that sort. If you've got any special requirements, special material requirements, impedance requirements, ITAR or anything like that, again would go into the fab drawings. So, and the fab drawing can be in your Gerbers, in that fab layer, or it can be a PDF separately, but it has to be clear about what is where. Now that's the old way of doing things, which is still the current way of doing things in most cases right. There are a couple of industry movements to create intelligent CAD files that tell an awful lot more, so you can have one file that has the layers, it has the layer stackup, it has information, the XY information, it has all of that contained within the single file. The most common one of those, in use today is called ODB++, and that was a proprietary file format, but I believe that it's been released into the public domain now. If you can output ODB++ which your software can, that's an awesome way to deliver the information to your assembly house. And you notice I said 'assembly house' there; for some reason the fab folks are often behind the assembly houses in these new file formats because the Gerbers work perfectly well for building up a board.
It is so true, although I have seen more of the modern, more complex, the board houses that do more complex things, they typically have ODB++ integrated throughout their factory, it really leads to more reliability, I think it's a good thing - and of course IPC 2581 right?
Mmhmm, that's the next one good.
Which has been, I was looking it up the other day preparing for this, and I was thinking its' been like 10 years, it's been a long time coming. And I don't know all the ins and outs, but I looked it up, it was started in 2004.
Wow [laughter] 14 years ago!
I mean, I thought it was a long time, but 14 years, and again I don't know what the stop gaps are, but like you said, almost every CAD, I think all the CAD manufacturers output those files
Gerbers, ODB ++, 2581. You talked to me a little bit about Gerber X2 - can you tell me a little bit about that?
Gerber X2 - I have no idea if it's going to catch on or not, or if it's going to be a viable solution, but at some point, the consortium that manages the Gerber standard, decided they'd better get with the program or Gerbers were gonna go away, so they have proposed a new standard, Gerber X2, and I don't think it goes in as in-depth as the ODB ++ or the 2581, but it does allow you to put intelligent data or metadata on top of the Gerber layers. So as I said with today's
Gerbers - I can't tell if a piece of copper is a pad or a pore, it allows you to do that sort of thing, so you can connect up what components are where and whatever information is needed to assemble them. I don't believe that that specification has been signed off on yet and I have a feeling that it's going to be a little bit of a 'too little too late' but I'm just speculating on that point so.
Yeah, and also IPC has, I think you mentioned to me, the D3-56 which is test points right?
Yes, they have I believe, they have test points, I think they even have the full IPC 2581 specification it even has room for the Bill of Material.
That's my understanding.
Yeah I think it's a whole cohesive across all the fab and all the assembly processes but again, it's not something I know a lot about and of course your NC drill files for fabrications. What
else do we need to talk about?
Well one of the, because those file formats are in such flux right now, one of the most
important things to do, is once you have picked an assembly partner and a fab provider, give them a call or send them an email and say, hey what do you prefer? It's even complicated to explain this so I have to tell people, if you have Gerbers send us the Gerbers, and if you're sending Gerber send us the centroid and any Fab or assembly instructions. If you've got ODB++ send us that, but still send us the Gerbers, just in case we need them with the fab house and we need the centroid for this, but not for this...
[laughter] Oh gosh.
Call your fab house...
Can you just send us everything in every format and...
-and that you know, the law of unintended consequences pops up there sometimes
because we will get someone who sends us Gerbers and then we'll say, hey by the way, do you have an ODB ++ and they say yeah, so they send that off. Awesome; except it's a different version. When you send multiple types of files, make sure they are all of the same version, saved at the exact same time...
-the revision it's a different revision you guys... okay. Keep your revisions, keep your old revisions out of the mainstream.
Yeah, what we found is it's real common for, even after a designer hits save for the very last
time, and sends off their files they'll tweak the silkscreen or they'll say, that component wasn't
available, let me use this one and they make these tiny little changes but sometimes it's going to a different package or you know, that part was a 'do not stuff' so let me just take it out of the design now, and so we get different versions of files literally two days apart.
Oh god bless us all, I don't know how we survive this industry. When Duane and I were
preparing for these, this podcast I was saying, you know I left the industry for 12 years and I knew there'd be like a crazy catch up, but when I came back I said I felt like Rip Van Winkle.
I can feel like Rip Van Winkle after leaving for a weekend sometimes [laughter] and I'll
think everything's cool and then Monday...
Yeah he says, I feel that way every Monday [laughter] it's so flippen true!
It is you know, I'll walk out on the manufacturing floor and one of our engineers will say,
hey Duane, because I'm out in the outside world a lot and he waves me down and shows me some component and asks me, have you ever seen this before? What do they do with this? What are we supposed to do with this? And it's like. Oh yeah, I kind of read about that, and I talked to an engineer at a trade show, about that, and it changes so fast and you know, the
changes are not slowing down, they really aren't.
And we're managing them with spreadsheets and multiple file formats just to make it fun.
Yeah and you know, some of it, is our own fault. Because we like to do things fast and you know companies, there are a bunch of companies like mine, who have decided that, gee everybody needs to do this faster than they used to be. And years ago, when I was on the OEM side, to get a board built, it was typically three or four weeks to get it quoted, then three or four weeks for he NPI process, before anybody gets that out in their line. Well those six to eight weeks, we now do in six to eight hours. And so, when you have all that much time, you can go back and forth to the
engineers, you can ask questions. Now you know, 2:00 in the morning one of those questions that were you know, years ago we would have had a week to get answered, now we need it, you know it's 2:00 a.m. we need the answer by 2:10.
We can't blame everybody else, we have to blame ourselves a little bit too.
Right.
I'm gonna blame you. All your fault Duane [laughter] anybody asks me from now on I'll go, it's
Duane's fault. I think a lot of our manufacturing folks would say the same thing, if Duane would just stop promising that.
Right yeah, exactly.
You mentioned a few problems that kind of come up during the chaos of all these different issues that we face and one thing was relative to rotation on IPC standards. Can you talk about that for a moment?
Yeah that's one of my pet projects or 'pet something.' The IPC specifies which pin should be at what part for zero rotation so you've got zero, 90°, 180°, 270°, 360° and anything in between, and what direction goes from zero to 90° on the front or the back, it's specified, it's in these standards, and these ones have been around for a long time. Well what I've found, is a large number of the footprints in CAD software, especially the CAD software that relies on user-generated content more than professionally generated content, a lot of those things, the zero - the pin1 zero rotation is wrong. So for example with an LED or a diode, the cathode is on the left, its horizontal pin one is on the left, and that's zero degrees rotation. We see them where zero degrees rotation has something vertical at 180 degrees, pin one on the right, all sorts of nutty things like that, and that's probably 80% of why we simply can't rely on data maybe even 90%. Theoretically, you should be able to output a set of files from CAD software, send it to a company like ours, and never talk to us and just magically get boards back. A huge portion
of why we can't do that is because so many of these footprints don't follow that IPC standard, and if it were a rare exception, well we'd assume they all do and catch the rare exception there. It's so common, that we have to disregard anything that any of our customers tell us about rotation. Which means we have to have someone look at every single part on that board.
Oh my gosh! It's like a bad version of pin the tail on the donkey. Can you guess which one is pin 1? Have a nice day - oh on all these parts - oh my gosh I don't know how you do anything fast.
It's crazy…
But the cost, I mean some of these parts are super expensive and if you rotate them the wrong way, and you fry them or you wreck the board like, that was a bunch of money.
Yeah we have we run across $10,000 FPGAs we come across ‘one of a kind' parts that are going into some space mission so yeah we really can't risk putting those things on wrong, I'm sorry there are only four these parts in the world don't blow it, okay.
Well and do we - like you said so new parts come out, but when new parts come out, sometimes the standard hasn't been written yet correct?
Yeah we saw that a lot in the early days of the QFNs you know, QFNs all the leads are underneath around the outside of the part and there's this big metal heat slug or ground slug in the middle of the part. The IPC standards didn't cover that yet, and a lot of the CAD software folks had never heard from manufacturers so they didn't know what to do with it. The footprints all had that big heat slug wide open, so then what happens, you put solder paste on that, there's a much higher aspect ratio of heights to volume in the center pad, so the part rises up, it kind of floats up and then all the pins on the outside don't connect and for years, for a few years, nobody knew how to do that, how to make that work properly. Again, if you've got a three week NPI cycle you can figure that out, but when you're doing it overnight... So we determined that you need a window pane solder paste stencil. Fifty to seventy-five percent cover to paste, and it works, but it was a couple of years before the rest of the industry caught up to that and with the tiny, tiny BGAs, point four millimeter pitch BGAs changed the rules on the pad and solder mask with larger BGAs you want non-solder mask defined pads, so you want the solder mask opening to be a little bit larger than the copper. Well with the point four millimeter pitch and
smaller BGAs, that causes the solder balls to squish, and you get bridging.
So you want a solder mask defined path?
Again the rest of the industry didn't keep up with that, because the component manufacturers threw these parts out, without figuring out how to build them...
That's wild.
Yeah and a lot of fun too, I think [laughter]
For those of us that are masochists and gluttons for punishment. [laughter] Okay in all that craziness that you've just spelled out for us. So for our listeners, tell us what a good or a great set, like a clean set of manufacturing files would look like if you could wave a magic wand, and you'd want to see a really clean set of manufacturing files come in?
Okay first of all, everything is the current and the same version, and everything was checked and double-checked just before sending it off to us. There would be a readme file, that includes anything that's non-standard is covered in that readme file, and it's clear, to the point, not wordy - it's not prose, including things like the the stack up. It would have a Bill of Materials in Excel format that has the information we talked about, and possibly even a few substitutes. And then
ideally it would have one of the intelligent file formats like an ODB ++ or an IPC 2581 - that would be the ideal format. If you're stuck with Gerbers, then it has to have a good set of Gerbers. Again with that stack up documented and a centroid file and of course we would love it if someone could could certify that their rotations were correct so we could believe the centroid file but that's really it. Ideally intelligent manufacturing files, a bill of materials, and Excel and a readme file and then if you are using Gerbers, then the Gerbers and the centroid.
Good - well hopefully that will help, hopefully people listen to this podcast and give you some cleaner manufacturing files Duane.
I hope so.
So, something you pointed out to me though, even if you got the perfect set of manufacturing files, we're not robots, and you said something to me: this is not a 'no touch' process.
Yeah.
-you can not throw it over the wall and go about your day so let's wrap up with your thoughts on that.
Well communicate you know, I saw a bumper sticker once that said: I didn't spend four years in engineering school to talk to people. [laughter] But the fact of the matter, you know, we will talk to you using a few sentences. We'll make it short. But talk to us, and anybody who's building your stuff, don't be afraid to pick up the phone and call them, or to have an email exchange.
I know we - a lot of us nerdy people/geeky people whatever, don't like talking to people.
But we have to, and do that, do not be afraid. And if you've sent your boards off, and you're expecting a fast turnaround time, be available 24 hours a day. Companies like us will typically work 24/6 or 24/7, and as I mentioned before, if something happens at 2 am, and things do happen you know. So yeah do we continue the build without it or stop and wait for more? We may need an answer at 2 am - be available, make sure that someone can get a message at 2 am, and then get back to your manufacturer as soon as possible if they contact you. And then do understand that yes, we are all human, we know you're all smart people and we're all smart
people, but everybody... you know it's a complex job we're trying to do
Extremely complex, god bless us all for even attempting to do it, but we do it. We do it and a lot of times we do it quite well so kudos for us in the industry. Well thanks for those tips and kind of clarifying what a clean package will look like. I know it's kind of a convoluted - there's no clear, single path forward. So I think that's really, it's kind of really basic but as you can see from our conversation it's a lot more complicated than it appears on the surface. So thank you so much Duane, for taking the time to clear that up and let us know what works and hopefully give some good advices to some designers out there.
Well thank you for giving me the opportunity I always enjoy these opportunities you know.
We enjoy having you always, and I'm sure we'll have you back again.
So well, that's it for our OnTrack Podcast today, thanks again for joining. Please drop us a message, let us know what else you'd like to hear about. Tune in next time. Until then, remember to always stay on track.
Wednesday Sep 19, 2018
Quick Turn Circuit Board Fabrication with Royal Circuits
Wednesday Sep 19, 2018
Wednesday Sep 19, 2018
From Tesla to consumer devices, Mihir Shah has been a PCB designer among the best. Now, as Director of Special Projects at Royal Circuit Solutions, he is pioneering ways to make manufacturing easy for printed circuit board designers. Meet Mihir and Jon Lass, co-founder and VP of Engineering at Royal Circuits, and listen in as they discuss manufacturing best practices and share various insights on symmetrical stackups, solder mask, and copper weights. Get a wide range of PCB design tips and learn how same-day turn times on printed circuit boards is possible at high-quality board shops like Royal Circuits.
Watch the video and read get all show notes.
Hey everyone this is Judy with Altium's OnTrack Podcast. We are glad to have you back again, the podcast continues to grow and we thank you for listening and I know that you are tuning in because I have amazing guests like I have today so I would like to introduce you to my guest but before I do I would like to invite you to connect with me on LinkedIn. I'd love to connect with you and share a lot of information relative to PCB design and engineering and also on Twitter I'm @AltiumJudy and Altium is on Facebook, Twitter, and LinkedIn so we like to have conversations with you, not just monologues; so please connect and make sure you subscribe to our podcast too so we can keep making these.
Today we are with a couple of great people that are involved in US manufacturing of printed circuit boards. I'd like to introduce you to Mihir Shah, who is Director of Special Projects at Royal Circuits. Mihir actually was an EE and has lots of experience - hands-on experience - being in the trenches and doing design work. His father right, it's your dad that owns Royal Circuits Mihir?
[Mihir nods]
And so his dad somehow sucked him into the manufacturing industry. So we're glad to have him there actually, we need more young blood and also, we have Jon Lass who is the VP of Engineering. He's also one of the original founders of Royal Circuits, so gentlemen welcome thanks for joining today.
Thanks this is great.
So Mihir, I'm going to start with you. Why don't you tell us a little bit about your background and then give us a little blurb on Royal Circuits?
Sure, so as you kind of alluded to I'm an Electrical Engineer. I started my career at Tesla Motors where I was working on a lot of the cool things with Model X, and Model X, back in the early beta days of that vehicle. I just got crazy hands-on experience learning how to design your own boards hands-on for everything, just do things quick and get a design approach to rapid prototyping, which was great. And then I went to Taser - now known as Axon - where we worked on consumer devices that are - I mean literally - the Taser device.
So I was more on the power electronics side of the Taser weapon and some things on the body camera so a really, really great experience albeit limited, but really great in the short time that I was a fulltime design engineer. And then you know, somehow, some way, my dad convinced me to join the manufacturing side of things.
Yay Dad!
I'm kind of - one of the roles is always like: look, you were buying boards and designed them for a while, now come here on the other side and try to make it as easy, clean, and simple as possible for people to order them now that you've seen often times, what a pain it is, or all the mistakes that you kind of made, or things that delayed the time, cost etc can help on the manufacturing side and now, Royal Circuits, just to give a brief overview of who we are, and kind of our main value proposition. We're a big US manufacturer of purely quick-turn, prototype, printed circuit boards. The whole idea is one, two, three-day turns in the Bay Area, same-day turns and weekend turns - totally acceptable, and all owned and operated by us, all here in the United States.
So we have two factories: one right here in Hollister where I am now, right in the Bay Area, and then we have a factory down in Los Angeles that's purely flex and rigid flex. We really focus on that technology down there, so we've been doing this for over 20 years. You know, we have our customers range anywhere from large tech companies like ones you've heard of, like Google etc. Students, Stanford, Caltech, UPN, MIT and military.We're ITAR certified, and then thousands and thousands of other customers in that group and more. So we do everything from simple two layer boards all the way to 30 layer, HDI , High Density Interconnect, PCBs, fab and assembly - no minimum order quantity.
So really, really focus on the low volume, super quick turn, with an incredible focus on customer service and making sure that people get their boards when they need them and at the price that they want them at, right here.
Wow, Jon can you tell us a little bit about your background in the industry and your history at Royal and what you do there?
Sure, so my background has been Engineering for about 30 years. I started out in the CAM/CAD industry and was involved in the very early days of photo plotting when we used to build boards with films that have, actual direct imaging as we're doing today.
My dad and I founded the company 20 years ago here in Hollister and we - like Mihir pointed out - it's always been about quick turn, 1 to 3 dating, prototypes, all the way from 2 to 30 layers and, very exotic type of materials and boards. So we've been around for 20 years servicing our customers and we still have some of the same customers 20 years later.
That's a good report card! That's an excellent report card.
That's how we look at it too.
Well my favorite stat about the company - just to interject - is that we really do have a 1 percent turnover in 20 years. I mean, I really encourage you to find another company in the United States that has such a low employee turnover. Everywhere I'm looking, Jon is a testament to that, people don't leave, we just keep growing here and in LA. And in some of the other kind of businesses that we run, same deal. Customers first.
Ok so I'm going to become a board industry geek for a moment but I want to point out something about that, that may or may not be obvious to our audience; but something that I've noted when you do work with a board house that has low turnover, your quality remains consistent because there aren't people coming in muddying the waters all the time, are on a learning curve, or trying to insert something and so your processes stay a lot tighter and cleaner. And that may be something obvious but it's just something that I observed over the years working for multiple board shops and assembly shops.
It was a statistic, before I chose to represent one of those places is, what is your turnover? Because I knew that would create a lot of chaos not only for me, but for my customers, because of the fluctuation, customers, designers, will say to me: I was doing business with XYZ company and all of a sudden - they were great for eight years - and all of a sudden they lost the recipe and I go: uh-oh, they have had employees change. I know exactly what happened. So I know, we've all seen it, maybe an obvious point but something I thought worth pointing out to our listeners.
We appreciate that point, and I will also say that our Production Manager's been here for 18 of the 20 years, so again, it does make a difference.
It does make a huge difference. And Jon, your tenure there and being - yeah that's just wonderful. That's again, a great report on you guys. So this morning what I thought we'd talk about is stack up and impedance, but from a manufacturing point - what you guys can teach designers and engineers that are laying out boards. How you can help them sort of avoid some pitfalls relative to stack up and impedance from a manufacturing standpoint?
So Jon, maybe I'll start out with you, or maybe you both want to kind of ping-pong this one for the uninitiated, let's just talk about what kind of implications there are specific to stack ups with materials?
I mean that's where you start.
Do we have enough time?
[laughter]
We could do a whole thing on materials maybe we need to do that? Because you just said you had a lot of exotic materials I'm like: oh they're one of those. Okay so all right, let's talk about materials, sorry.
You know, I'm just starting - again just the very basics. Our main is FR4 high-temperature FR4 materials but we do get into a lot of Rogers materials for the RF type designs a lot of hybrid combinations a little bit of Teflon so just there's different variances on what you can use.
But diving into stack ups, what a lot of people don't think about from the impedance standpoint is, what are we doing with the the outer layers as far as the copper weights and the plating? And I'm touching on that real quick, because when you start out with a half ounce copper foil and then you plate up another additional ounce - sometimes when they're doing the modeling in the software - they're putting in half ounce and they model it and they get a certain number. But in reality when you manufacture it, you're plating on the surface, so a lot of times I'll get, from design engineers: well my model shows that it should be, 50 ohms and you guys are coming out at 55 ohms?
It's like: well, you're not taking into consideration all the plating on the surface and that makes a big difference. And so we get a lot of that where there's a lot of model software out there on the internet people can go to. We use a software called 'Archeo' it's a very very deep system, as far as it actually takes into consideration all the dielectric constants of the materials you're using in your stack up.
For example, different cores are built with different prepregs, and so they have different dielectric constants. Some of the modeling software on the internet gives you one setting so you can put in 4.1 or 4.2 for your DK value but in reality, depending on how the materials build you have different DK values that can range all the way from maybe 3.8 to 4.2 on a certain materials like these; I sold a 370 HR for example.
So when creating the stackup, we have all of that in there, we have all the pretty products the laminates that are being used, even the LPI and all the dielectric constants and when we're modeling that, impedance becomes very very accurate compared to the models are on the internet.
So - I wanted you to pause right there, you said LPI, so that's Liquid Photo Image of a solder mask. So do you typically put the solder mask in when you're doing your models?
Absolutely you do, because that's a big, big critical part. Another example - I'm glad you brought that up because again, they go out and model on the internet; they're not putting on the solder mask, they're not putting on the copper plating. As I mentioned, they get a completely different value, and then when we come to model it we're going back and telling them we need to change their stackup they may have defined on their fab drawing, because it doesn't meet the impedance requirements. And also you do get a lot of designers that understand that and they'll put notes on the fab drawing saying the manufacturer can adjust the dielectric, spacing, or the trace width within, plus or minus 10% to obtain that value.
Yeah, and like you said, I think that's a good point, say in the case of Isola, or any laminate, they might put a datasheet that’s about 3.8, but it's not exactly 3.8, it can vary in a minor way, from lot to lot, is that correct?
Not so much lot to lot as it is from material to material so they - if you build all the way from 3 core to 47 core, they're using 106 and 108s and these are all prepreg styles that I'm mentioning, and each one has a different dielectric constant. So if you get a combination of them, you end up with a different value - and that again - depending on how your stackup is generated, one discussion Mihir and I had earlier today, is about designers that specify in their fab drawing the stackup they want you to follow, and they can send it to board house X, Y and Z but if, for example, let's say they have a four-layer and they want to specify they want 8 mil dielectric spacing between 1 & 2 and 4 & 3.
Well, we may use a different series of prepregs to obtain that than another fab house and again, DK values - different impedance readings. So all that comes into play.
Yeah and that's a trade off, that's a consideration the design engineer has to make in terms of how they're doing the prototyping, what the outlook is for them, and the turn times and the costing you know, there's other factors outside the actual design of performance on the circuit itself because if you do it, and you have it once, then you say this is my design so at least you will have more consistency amongst different manufacturers because you see, I need these materials, I need backup I did it - do it. But you'll have consistency in the final product but you more I mean most certainly, will not have consistency in the turn times. The available materials that different guys have, especially when you start getting to the more the exotics, and the high-frequency stuff.
So that could start playing into effect and people charge different amounts for it based on the lead time, what they have in stock, what they want to charge, etcetera as that gets complicated but at least, it'll be more close to a similar design on revision vs. if you say, look: I'm just gonna let the manufacturer do it and tailor it towards what I can get quickest and at best cost that'll still give me my main factors and whether they're controlled impedance or stackup height or whatever - and let them do that. So that's kind of the two different ways that people can go about designing.
My impression Jon, before you go on, is that a lot of designers do kind of hand off that stack off to their manufacturers. Do you think that's true?
Yes, we do get it kind of both ways. In some cases, we just get a stackup, for example, if they want it to be 062 plus or minus 10% that gives you the layers that have the impedance requirements, and then we go and generate the stackup and manufacture the board. To me that's probably the more straightforward way because you're guaranteed you get what you want.
Sometimes they're specific about what they want. They call out the dielectric spacings, the core material is everything and now you have to build that stack up, then plug in their numbers and model it, and then it usually doesn't come out the way they thought it was going to. And again, we touched on two reasons why.
So you kind of get a little bit of both. But what I was gonna start saying is, that we also offer a service, a stackup service that you can come to us at pre-design. You've got your board all laid out, you're ready to do your routing, and you can come to us and say: hey, I have a six layer and eight layer design, this is the material that we want to use, and you can tell us a little bit about your design. Which layers are plane layers, which ones are the signals. We don't look at the reference to this is, ninety ohm diffs, and 100 ohm diffs, and then we can go ahead and model that stack up at that time. We can come back and tell you what size traces to use for the single-ended, the tracing space for the differential pairs, the copper weights, everything. We can come back and give you that complete stackup.
So now, that's using our materials. Our DK values, our stackup software, and then when you go to Roger design - if you use those numbers - then when we get back your design and your stack up - the project’s done.
Which I think's a really great model, because then you're doing this partnership - the designers telling you where they're trying to get - you're actually informing them, from a manufacturing standpoint, best practices, and I love that whenever that happens. I wish it happened more.
That's right, that's free of charge - again right at the beginning stage - to me that's the smoothest way to do it. And then you have a stack up you can actually send in with your data package and you'll be guaranteed you'll get what you want.
That's awesome, what a great service I love that.
You've talked a little bit about it, is there anything you want to add? The distribution of copper I get. I used to specialize in RF and microwave boards and that issue you talked about where they model it without the plating ending up on the outer layers right. The inner layers it doesn't matter, but the outer layers, you have to do multiple planing cycles and then it's completely outside of the range of what they simulated and I'm like: I don't know why, and without a fundamental understanding of the manufacturing process it's easy to see how that could get missed. Is there anything else you wanted to talk about? I'm gonna ask you guys three or four or five tips and tricks to give people who are listening some takeaways. But before I do, is there anything else you wanted to add relative to stackup in regards to manufacturing or distribution of copper?
Maybe just a brief... oh sorry Jon do you want to go?
I was just gonna touch on, you were talking about outer layers and then inner layers. If they want to use heavier copper, I like to point out that that's great on plane layers because when you have a heavier copper, your z-axis is higher and now when you go to put the prepreg in, you have to have enough resin to fill in there. And if you don't have enough resin then it can cause delamination or other manufacturing issues. So again, to point out, we get a lot of that too. We get a lot where they want 2 ounce copper on the inner layers, and they'll mix their traces and planes together and they'll be putting 4 mil traces on 2 ounces of copper. That doesn't work, that doesn't work at all.
Yeah and then you have a trace that looks like this [gestures] right like or this - they're not this any more there cuz that's a hard if... yeah it's not a good idea.
So just keep in consideration, from a copper distribution standpoint in layers. You have to nest prepreg in between them, it definitely makes a difference. So, if you're dealing with half ounce copper, no problem - you can pretty much do whatever you want. When you start getting above one ounce, then it starts changing the ballgame. So, from a proper distribution standpoint, just take that into consideration when you have - I'm going back to impedance - but when you have impedance on the outer layers and you're referencing to a plane layer underneath. Try to leave it all solid plane without mixing it with signals. That makes a big difference.
Because now, you have a nice, consistent, even, solid dielectric spacing between the two - so that's a definite plus. Like a six layer, for example, where you have power ground on layer 2 & 5 and then 3 or 4 signal layers, you have to use a lot more prepreg to nest in between there. So again, try to pull up most of your dielectric spacing between those two areas because you're going to need more of it to nest the prepreg. So that's a little bit about copper distribution.
All right, all right guys, so let's talk about some real practical takeaways right now for designers and engineers who design boards that are listening today, from a manufacturing standpoint. I'm sure that you see some of the same oversights being made on a consistent basis. Can you give us three to five tips and tricks; things that designer should look out for when best design for manufacturing practices that you guys see. Mihir, why don't you kick off?
Sure, well mine has a bit of a tie-in more on the design side, because that is more of my background especially that's right now, but there's really two main design areas when it comes to stackups and manufacturability. It's the whole RF analog side and then this digital - high-speed digital - side and they're kind of characterized by two very different, but very heavy driving factors. On the RF analog side you generally find your designs more influenced by the necessity for a low dielectric constant, low signal loss, low leakage, and then generally these have a lower layer count so you really need a low and uniform dielectric constant and all these other things.
So your choice of exotic material is gonna be far more important. But you don't necessarily need to work - that's gonna be more of an important bigger part of your cost, and a factor in your design decision. It's just more important to the design. Whereas with a lot of more high-speed digital stuff, these are usually a way higher layer count, and they have all these other things like burying blind vias, really, really tight traces, and just all these crazy ICs that have like a hundred pins of BGAs that needs all sorts of fan-out etc, and so your costs on that was gonna be way more driven towards the actual manufacturing time and the complexity, and to a lot of people it sounds obvious probably, on this podcast, it is.
But I mean you'd be surprised even as you're designing stuff, people really don't fully understand that buried and blind vias, while they're so easy to throw in on in Altium and just say, this is great, everything routes up perfectly. It does add a lot of cost and time. You could manufacture it, but it's seriously gonna impact your design when you have to do board back, so that's gonna be far more important than generally your choice of material. But obviously, as layer count increases that cost is going to be driven up too. So things like that. You have to take into consideration the differences in the designs and things that engineers are looking at when they're designing them and how that plays out usually in cost and lead time.
There's a lot of trade-offs aren't there?
Yes, that's right.
What would you say Jon?
Well let's tackle unbalanced stackups for a second. Because we get a lot of that-
Pretzels?
Yeah pretty much.
So again, I mean one of the things you need to take into consideration is, you want to have a symmetrical stack up. A lot of time too - especially if they're using hybrids - so they'll put a thick ten core Rogers on the top, and then something thin on the bottom. And again you want to have a balanced stackup, otherwise you're gonna end up with a warped board that to me is a very, very key thing, is to keep it symmetrical. We'll get those stack ups, we'll have to go back and tell them: listen is it possible, the chance of warpage, and try to explain to them.
They need to be symmetrical, so that's something to take into consideration from the get-go. Another one that we get a lot of, and I think I touched base on it a little bit; is to take into consideration the copper weights you call out in the trace and space that you're routing. Because it makes a big difference. So you know, if you're going to be doing a three mil trace with a three mil space, we have to start with quarter ounce copper and then, on the outer layers we have to plate on the surface. If it's on the inner layers, you can do small trace and space on half ounce copper. But once you start getting to two ounce copper and above, you need to be around six and seven mil tracing space.
And we get a lot of that, where we have to go back and tell them: listen your design has four and four you're calling out for one ounce copper, two ounce copper, it's not possible, so we're gonna have to go ahead now and reduce the copper weight, or even worse, that they have to stick with a heavier copper. They have to go redesign their board and lose time.
Explain that, it may be obvious, but explain why that's impossible? I've run up against this a whole bunch of times, but explain because it may not be as obvious as it is to you and me Jon. Why can't you take two ounces of copper and do a four ounce or 4 mil trace or three mil trace, what happens?
There's two scenarios: one is when you give us a design that's 4 mil trace for the 4 mil space between trace and trace, and trace and pad. In order to finish - after etching that trace - we have to do what's called an x-factor. So now we have to increase that trace, X amount, might be one, two, or three mils depending on the copper weight. Because again, having copper it's a higher z-axis. So when you actually have a further distance to etch down to the base of the copper to get down to the laminate, you start losing the feature size as you edge the copper down. So we have to increase that feature size.
So if it's a 4 mil trace and it's 2 ounces of copper, we might have to increase that to a 6 or 7 mil trace. But if your air gap is 4 mils - now we're reducing that air gap down to 2 or 3 mils - which is not manufacturable. So that's where you'll be coming to the problem. And again you also have peel strength. I mean if you have a 3 or 4 mil trace on two ounce copper, I mean the chances of it actually peeling off the laminate is much higher, because you have a certain peel strength. So again, you're not gonna have a small trace on a heavy copper feature for various reasons.
And maybe even in more layman's terms, because this is what helped me understand it when I was doing - because you really don't learn this stuff when you're studying like for engineering or maybe, I don't pay attention.
No, you don't learn it, you don't learn it, you're right.
Simplistic, the thing is people, maybe we could even put this up on the video I don't know if you can add that or add a link? If you picture traces from the side view they're not straight up and down. Right?
Never.
They're at an angle, the reason they kind of look like they're little trapezoids - is because the top of the trace is under the duress of the edge - about the actual chemistry - a lot longer than the bottom. So as it edges down, the top is getting whittled away more than it is at the bottom. So you tend to add an edge like this - if your traces are really close together, you don't have that space in the middle. It looks like you have all the space in the world at the top, when you get towards the bottom of that z-axis, they're actually touching, so you can short out traces that's like the simplest example without getting too deep into everything.
Can you undercut in that scenario or am I thinking of it backwards?
Yeah, undercutting is a term you kind of get on the outer layers, but when you have the dry form you can kind of get it undercut but for the most part it comes to geometry. I mean, you have a very tight tracing space, and first of all, you have limitations on your gap. And even if you could increase the trace big enough, you're gonna end up like Mihir pointed out, with a very small trace on top and a larger trace on the bottom.
Yep it makes sense.
Oh yeah a lot of mechanical electrical kind of issues.
And as well, I have a friend in the industry who was in the board industry for 40 years, and he used to say: it looks good on paper, but he said physics trump's theory right? Like theoretically, it should work right, but he goes: but physics wins out every time. So Mihir, any more kind of practical design for manufacturing tips that you can think of, or Jon, either one of you?
I think we kind of - if people take at least a few tidbits from what they heard today - there'll be an immediate ROI on their time listening, to the success and speed of their design.
Good, well I'm excited to announce that Mihir and the Royal team, will be joining us at AltiumLive as our sponsors. They just let me know that today, so I'm very excited!
So I'm sure you guys will bring some sample boards, or some video and some great assets that they can look at. They can talk to you one-on-one, learn some more tips and tricks, face to face just gather information, which is sort of the magic of AltiumLive. Our goal is to just put the design community in a room with the supply chain, with people that are very knowledgeable, which are veterans in the industry and just let them rub shoulders and start creating new solutions or just collaborating for successful designs and take some of the pain out of it for all of us. So we're delighted to have you guys in San Diego in October.
I really needed an excuse to come to San Diego.
Right! I know, and it's on Coronado Bay, so we're staying at the Loews Coronado Bay Hotel so there's water on three sides of this hotel, and it's in October, which is like, October in San Diego is like heaven. It's like 73 degrees, on the water, so...
You already sold us!
Right it sounds like if you're not coming to learn some design stuff, at least tell your boss you are, and get a nice trip to San Diego... just kidding.
So anyways, we're glad to have you and I'm glad to to get to know you guys a little bit more. I know of Royal but I've never gotten to know you until this last week and so it's been a delight to get to know you both and learn from you. And thanks for sharing your DFM wisdom with our listeners, and we look forward to engaging with you more at AltiumLive, and we'll be sure to share many links.
I think I have eight links to share from Royal and you can dig more into what they do, who they are, and get to know them a little bit better as I have this week. So I'm sure you'll enjoy that. So Mihir, Jon, thank you again so much for joining today. Thanks for joining on our podcast.
Thank you, thank you Judy.
Well until next time please subscribe, join, engage with us at Altium we always enjoy learning from you and learning about what you would like to learn about. We're only making guesses unless you tell us specific topics you would like to learn about. So keep the comments coming. We look forward to engaging with you next time on the OnTrack Podcast. Until then, remember to always stay OnTrack.
Tuesday Sep 18, 2018
Seamless Global Transfer with Julie Ellis from TTM
Tuesday Sep 18, 2018
Tuesday Sep 18, 2018
See all the show notes here.
Julie Ellis started her career as a representative for a semiconductor manufacturer after completing her Bachelor’s in Electrical Engineering. Now she is a Field Applications Engineer (FAE) at TTM Technologies, the third-largest circuit board manufacturer in the world. Listen to Julie and Judy discuss seamless global transfer and recommendations on working with offshore fabricators. Learn how to avoid excessive technical queries and how to migrate from prototype to production while optimizing global processes.
Bonus update on AltiumLive: Julie and Carl Schattke will be presenting at AltiumLive 2018, introducing new stackup and impedance tools in Altium Designer 19, so be sure not to miss them!
Show Highlights:
- Julie Ellis did a presentation about Documentation at AltiumLive 2017.
- What is Seamless Global Transfer? Transferring PCB manufacturing from onshore prototype level into production and offshore.
- Julie started her career at Hughes Aircraft, where she completed her Electrical Engineering Bachelor Degree - best decision of her life
- More women (not just circuit board barbie) need to get into STEM! #WomenInTech. Julie always encourages young women who are interested in STEM, to get a degree that will enable them to move into fascinating jobs with a variety of opportunities.
- Julie’s first job was as a semiconductor manufacturer’s representative; realized she liked the circuit board side of the business more than ICs and migrated over.
- On TTM: It’s like working at Google for circuit boards, I can always call someone for answers about manufacturing best practices.
- Seamless global transfer - the concept is that you aren’t just designing for the prototype but for global manufacturing i.e. avoid 100 technical queries
- What makes migrating over such a difficult process? Because the 6-Sigma 6Ms, are not the same when it transfers over to Asia.
- What are the 6Ms? Method, Mother Nature “Environmental”, (Man) People, Measurement, Machine, Materials.
- Equipment sets are different for mass production, production lines are longer, there is not as much human oversight, production lines must be scheduled and you cannot stop/start the process. The tolerances are different and they need to be accomodated in the designs.
- Throughput and drilling is always a bottleneck and to reduce this and reduce turn time, mass production sites have tweaked processes to get the highest yield.
- Internationally the general rule is 4 mil lines and spaces on half ounce copper; 10 mil is the most common size drill which results in an 8 mil finish hole size.
- As you go up in copper thickness you need to add a little bit to the pads.
- Blind vias are the ones that are on the outside but end up on an internal layer.
- Buried vias are buried completely inside the board.
- Working with offshore production house while still in prototype development phase.
- Recommendation - design for volume and technology. Qualify the design for the final production region and technology.
- HDI (High Density Interconnect) is anything 0.4 mm pitch and under that has a track running through the pads.
- Judy wants to throw everyone inside a fab house!
- There are at least 30 different processes required to manufacture one 4-layer board.
- Julie works directly with Carl Schattke and they will do a stackup presentation at AltiumLive 2018
- Materials are a significant cost in Asia, whereas here in the states the material is less of a cost (20% in USA, 50% in China).
- With production panels where you're trying to get as many cookies cut, you also need to consider and discuss with your manufacturer the tiny 2x2 inch pieces.
Links and Resources:
AltiumLive 2018: Annual PCB Design Summit
TTM’s Interface Between Designer and Fabricator
Hi everyone this is Judy with Altium's OnTrack Podcast thanks again for joining. We're happy to have you again.
I would like to continue to invite you to AltiumLive, and I also wanted to put a shout out that we have a call for presentations right now, so if you are an Altium Designer user, and you have some tips or tricks or some kind of breakthrough you've had on design please contact me at Judy.warner@altium.com and I'd love to hear from you ASAP.
We'd love to have you present in San Diego or in Munich. Munich is January 15th through 17th and San Diego we are there October 4th, and 5th so look forward to hearing from you all.
Once again I have another talented and amazing guest with me; Julie Ellis from TTM technologies which as you know is one of the largest board manufacturing companies not only in North America but in the world today so Julie is an FAE at TTM and a very well respected technologist as well as a dear friend.
So Julie, welcome it's good to have you.
Thank you.
So Julie presented at AltiumLive last year on documentation. I've sat through many of her talks and learned much from her, so today we want to talk about what it takes to move jobs from onshore prototype level into production and offshore. She calls it seamless global transfer but before we get into that we'll hear a little bit about Julie's background. We both started in the printed circuit board industry in the 80s - which dates us a little bit I know - we're not going to say the year we're just gonna go with the round numbers the 80s but I always...
-we were child savants though so we say we were 12
-we were 12
-five
-okay five, yeah we were five.
So Julie just came in and noticed my super cool Career Barbie of 2018, which is a Robotics Engineer Barbie. She's got circuit board patterns on her shirt and a laptop, she kind of looks like us, so we're just gonna call her Circuit Board Barbie and you know blondes... smart ladies you know. Finally, there's a Barbie we can really relate to, and we want women to get into science and STEM and everything - so go for it and aspire to be this Barbie here.
Right on, yeah! Girl Power. We want to get more women in here, and it's just about exposure and motivating others, so we hope that throughout this podcast we inspire maybe somebody to give a girl a little nudge out there. We've enjoyed long enjoyable careers. So, okay Julie before we get started, why don't you kick off and tell our audience a little bit about who you are and your background - how you got into this wonky industry?
I am Julie Ellis; I started as a Design Engineer at Hughes Aircraft Company. I was awarded a student engineering scholarship there, which paid for most of my schooling - the rest of my schooling after I moved out here from Iowa - so I always tell everybody that getting a Bachelor of Science in Electrical Engineering was the best decision I've ever done in my life, so I really do encourage people. If you're interested in Math, Science, Biology - anything - get a good STEM degree so that you can always move forward into interesting, fascinating jobs with a lot of variety of opportunities.
It's a really, really good way to go and I encourage youth and people to get into this kind of field. So I started as - once I graduated from Cal State Fullerton - I stayed on it until the 1990s when things got really tight in the military market, and I was on loan to one department, but I couldn't hire in, so I took the first job that was offered to me as a semiconductor manufacturer’s rep and I had circuit board industry or circuit board experience at Hughes and as a rep I also had a couple of circuit board lines and I really, really liked the printed circuit board side even compared to the ICS and memory sales and everything. So I ended up migrating toward the printed circuit boards. Fast forward eight years, landed a great job at TTM as a Field Applications Engineer just a little over four years ago and it's been a fantastic opportunity.
TTM is the world's third-largest printed circuit board fabricator, and we would probably be number two if it didn't include Flex because the top two manufacturers have a lot more flex and rigid-flex than we do, so I'm surrounded by experts in this field. It's like living in Google for printed circuit boards because whenever I really want to know something I can go call somebody within my company and find the answer, so it's it's really good working here.
Really it's impressive, and you're right - like you really can go to anyone to get the latest and greatest information on manufacturing best practices which are really, really fun.
So we wanted to talk today about Seamless Global Transfer, and I know that we've talked a lot on this podcast about there's no such thing as the quick and dirty prototype so why don't we just jump off from there? Like what does it mean? So you design a board it's gonna go into production, but you've got deadlines, you need to crank it out really quick, you crank it out really quick and then it's like: hey it works let's migrate offshore!
[laughter]
That’s right - that way exactly.
That would be like the worst case scenario, like you heading for Niagara Falls and not knowing it. So why don't you talk about the myth of the quick and dirty prototype and why you really need to think about global manufacturing up front while you're just developing the circuit board and designing it?
Yes, so Seamless Global Transfer is the concept that you're not just designing for your prototype to get it through a quick turn shop here in the United States in five days. Because I worked - one of the numerous positions - was as a Circuit Board Commodity Manager and a contract manufacturer and a lot of the projects we got had already been tested and proven and developed here in the United States. They sent it to us for mid-level production, we’d try to send the parts overseas, and everybody would come back with a hundred technical queries and say: we can't build it because we don't have this capability over in China. Oh, you need to change this on the design - it's not going to work, and by the time you've given your job to a contract manufacturer your engineers do not want to make changes to the design that they've already tested.
So global seamless transfer plans ahead and thinks about: what is our migration path from quick turn development prototype and taking it over until long-term production and so there's a lot of background that goes into that, and that's what Judy and I wanted to talk about here.
So what is it that you think that makes that migrating over makes that a difficult process?
Because the Six Ms: man, machine, materials, environment - which is another M that I can't remember. Everything is not the same when it transfers over to Asia. The equipment sets are different for mass production, the production lines are so much larger and often much more automated, so they can't get the human element, you know. Watch this, watch that, we don't get the babysitting of our project over in China like we can here. In Asia or China, we have to schedule the production lines, and you can't just interrupt a line there to quickly throw this job in front of everybody else. The schedules are a lot different, the process tolerances are different, and because the process tolerances are different, we have to accommodate those in our designs.
Okay, so there seems to be a perception anyways that once we have a pretty robust design here that we can just kind of throw it over the pond. Why is that, I mean you just talked about some reasons but what are some like tangible snags you're gonna run into if you try to do that?
A lot of it has to do with the drilling. Like over in China most mass production shops, except for the really advanced HDI shops which would all go laser micro vias all the way through, as a rule don't drill using six mil drill bits because they're expensive, they break and they can't be re-sharpened and they break more easily and they have to be changed out twice as often as bigger drill bits. And bigger drill bits can be stacked, or you know, panels can be stacked. So if you can drill two or three panels at one time you've just got your throughput and drilling which is one of the largest bottlenecks in fabrication. You reduce your turn time significantly and time is money. What we're paying for in printed circuit boards besides materials, is the time it takes to get through the processes. So Asia and mass production sites have all tweaked their processes to achieve the highest yields, in the least amount of time, at the lowest cost. But there is a sacrifice to that and sometimes at the sacrifice of we need a better, bigger pad around a drill hole. We're going to stack two or three panels high instead of drilling a six mil drill and our plating processes are a little bit different so we may have to have more edge compensation. Which means that, that will drive a little bit larger requirements for line, width, and space.
So on those, is there a recommended - that's kind of a broad question - but are there recommended kind of hole sizes and pad sizes and/or trace and space sizes to help on the throughput? If you have it.
Yeah kind of the general rule of thumb internationally, is 4 mil lines and spaces, on half ounce copper is a good start. Anything under that on half ounce copper is going to be a premium. And ten mil is the most commonly sized drill which would drop you down to an eight mill finish hole size. And we'd like to see the hole size plus ten mil for the pad. So if you've got an 18 or an 8 mil finished hole size, we would drill it probably at 10 or 12. We'd like to see at least an 8+, 10 and 18 mil pad on that hole. That's just for a single lamination through-hole in multi-layer printed circuit boards. As we go up in copper thickness, we need to start adding a little bit to the pads.
Okay, and how does that change when you start adding buried and blind vias in?
It depends on the construction. If we're talking like a real traditional blind via board; blind vias are the ones that are on the outside, and they end up on an internal layer. Buried are vias that are buried completely inside the board, and those are different technologies. But so if we're talking standard blind vias where we might have 1 to 6 and then 7 to 12, both being blind via stack-ups, we would actually stack up the material layers 1 to 6, drill and plate, and then we would stack up the materials layer 7 to 12 - drill and plate. And then we would laminate all those together, and then we would drill and plate and etch the outer layers.
So those definitely have different rules because the two outer layers already have plating - additional plating - on the outer layers which means that we have to etch through thicker copper because of the foil plus the plating, and we're going to require slightly bigger line widths and spaces on that particular design.
So one thing we were chatting about as we were preparing for the podcast, that I thought was obvious, but also fascinating, is the idea of working with your - you know, I kind of want to move into now, sort of takeaways for our audience. So you were talking about working with your offshore production house while you're in your prototype development stage which I think is kind of counterintuitive. I don't know, is it?
Actually, if we are in the prototype development stage, it's the best way to do it because if - I always recommend that my clients design for volume. Whatever their final volume is you know, we all know the term DFM, but we really have to take it to heart to figure out, qualify the design for the final production region. Final production technology, whether it's a single lamination or a multi-lamination that's not HDI board like I just brought up, or whether it's an HDI board that has blind and buried vias, but with laser micro vias and advanced HDI board which I categorize as anything 0.4 millimeter pitch and under, that has a track running through the pads. So if you start at your before-prototype stage, qualified the design for the volumes and the technology so that you can pick your final production sites, get the design guidelines for those sites, get the stack up for those sites, and have the stack up and the design guidelines identified before you even route the board.
And if you do that then you're not going to route a whole board, send it over to China, and China is going to say: oh sorry those line widths and spaces, there's not enough space for us to compensate the etch and artwork during etch, we can't build it this way. Go increase your spaces, and if you don't have room on a tightly designed board, or if your pads aren't big enough to achieve the annular ring that you're asking for, your design is no good for manufacturing. So my term is ‘design for volume,’ but it means whatever your volume is. And the reason I'm doing that, or I'm saying 'your volume' is because we have customers that do 200 printed circuit boards a month, and we have customers that do a million circuit boards a month. And the shop that does the million circuit boards a month is not going to take the 200 circuit boards per month order, but they have a much higher level technology - so I can't design for that technology knowing that I could never run it in that particular site.
Right, so it's both volume and technology.
I feel like it's such a good service, in many ways on the prototype end, that we can kind of do push-button ordering now, but I also feel like what's has been lost is how complex the fabrication process is and I just wish - I want to throw everyone inside a fab shop. Because it's like when you - think you can just push a button and then a package shows up on your door; you know what I'm saying?
That every shop is a little unique is for a variety of reasons. It's not - for reasons that enable different types of technologies - they do it with high intention and lots of precision and all of that, and so you have to design for that shop. It's not just push-a-button and out it comes. Especially the more complex the board gets, so, on the one hand, I'm a fan to get the prototypes out fast, onshore when you can, have maybe available that kind of service. But on the other side, if you're going into volume, I don't know - I think it gives people sort of a false perception of what it's like on the other end.
Talk about - I think you mentioned this stack up; getting this stack up right at the... I really like that DFM right, design for volume, that was kind of a new concept to me that you introduced me to. So you're saying that the stack up should be kind of vetted and worked out with the volume as well as, what kind of board, what kind of technology buried/blind vias, you have the space levels to also work out the stack of details.
Yeah we need all that information to be able to create the stack up because most of those multi-layer boards with VGAs also require controlled impedance like for the high-speed digital that we're doing all the autopilot, industrial controls, medical controllers, everything seems to be working off some sort of USB and PCI, and we need to manage the controlled impedance. Controlled impedances based on line width, space, and how thick the dielectric is and to a little teeny effect, how thick the copper is. So we have to play all these together while creating a stack up and also keeping track of, if we're doing stacked or offset micro vias. We build those from the inside out and just keep adding layers, drill the outer layer down to the next layer, then on both sides then we add two more layers drill the outer layer down to the next layer.
But each time we do that, we have to figure out how we're going to plate those and how thick the plating is going to be and those are process variances are you know. There are process capabilities and variations from site to site, and there can be unintended consequences along the way, like putting additional copper on that outer layers - it's the more complex it gets you have these: if you do this, then this you know, what I'm saying there's so many!
Anybody who has seen my presentations knows that I always say that I'm always splitting hairs. Because a human hair is about 2.5 to 3 mils in diameter, and I'm always worrying about unintended consequences because if a customer comes in and they say: I want thick plating inside my hole walls you know, give me 2 mils of plating inside my hole walls. Well for one I can't think of one fabricator in China that would do that. The IPC standard for class three is 1 mil average plating in the hole walls. But the other thing is, remember whenever we plate inside the hole walls we're also plating the surface, the outer surfaces, the thicker those outer surfaces get, the harder they are for us to etch fine lines and spaces.
Well, why don't you just put it through the machine that just spits out the board Julie?
We need a magic machine!
If I could do that I wouldn't have to be here... I'd be somewhere on my own Island in Bora Bora...
Barbie we need a magic machine to spit out - maybe Barbie will get you to know either a Barbie plane and maybe she'll have a Barbie magic PCB?
That'd be great.
Then you know, in Barbie's world I think we'll just spit it out, I know - it's very complex and by the way. Let me stop right here and say that Julie helps every top brand that you could probably think of in Silicon Valley and beyond; helps them to do their stack-ups and come up with these you know, calculations to help work out all this hair-splitting and she's very skilled and capable. And that's why she will be presenting at AltiumLive with a senior PCB designer who she works with directly which is Carl Schattke, I cannot tell you what brand he works for, or I would get in trouble, but suffice it to say he's in Silicon Valley and works for the top electric car manufacturer and I am delighted that Julie and Carl will present on stack up on this very subject, and you couldn't get two more qualified people - I’m so excited that you're doing that.
Thanks, we are too - I think it will be fun.
It'll be really fun, and so they're so used to being deep in the weeds they'll be such a resource.
So before you move on though, it's not just the stack up, it's also the pad stack line, widths, and spaces that need to be provided to the customer with the stack up. Because we want to make sure that they know all of those design requirements before the board guy starts routing everything.
You talked about DFM and DRC's for final site and prep for the prototype. Is that - I just wrote myself a note here - have we covered most of that here?
Yeah, we have for the stack up and the design rules. But one thing I'd like to bring up is everybody's trying to stay competitive and because of the processes and the way that production panels are laid out in Asia. Materials are a significant cost over in Asia compared to here in the prototype shops. Here we pay for the quick turns, for the setups and things like that which are insignificant compared to those. So the material here is only about 20% of the average cost compared to 50% of the cost in Asia.
So if you can also plan your size to fit well up on a production panel so that like, imagine an 18 by 24 inch production panel, and you're trying to get as many cookies cut on that production panel, but you also want to think if you've got really small pieces your assembler is not going to be able to load those tiny little 2x2 inch pieces. Their conveyor equipment can't hold them, and it would take them forever to go through those linearly, so another really cost-saving exercise is to work with both your fabricator and your assembler to come up with a multiple up-array for smaller boards and also make sure that you know whether you've got enough clearance on the two long sides of your array, or your printed circuit board for the parts to be conveyed through assembly.
There's sometimes parts hanging off the edge which really makes things fun.
Yeah and that needs to be planned for in advance, whether: do you need an extra rail on a leading edge, because there's a big connector hanging there, or is the assembler going to put that on after the fact? But if you also take into account design for assembly - put all your test points on the board because once the board is designed and you can access test points, nobody's going to be able to go back in and design an in-circuit test fixture or functional test fixture and unpick those plates.
So don't just design for volume. Like I said really, truly design for DFX, design for fabrication, assembly, test, and long-term reliability.
Good, good, good, good advice. So can you give some real-life examples from your real life career? We won't name names of brands but suffice it to say there; you work with major consumer brands that if we could say names everyone would recognize them and tell us some of the, you know challenges that they had by actually not thinking about some of these ideas ahead. And these are the brightest of the brightest - I think what we want to share here is, everybody is challenged in this area, right? It's a challenging area, so we're not saying, oh we're so smart, and you know the audience what do they know? No, the top designers, the top printed circuit board designers almost in the world, are challenged by some of these issues. So just talk about some real-life examples and how it went wrong or how it went right?
Okay one real-life example in the last quarter was a major commercial customer like you said, they had worked with a - probably a Silicon Valley shop - they built their boards, tested them out, proved them, and they wanted to go into mass production. Their start date is like August, to start delivering mass production so that they can you know, start shipping their product. Well it turns out they had a design that had a six mil drill - mechanical drill through a standard thickness board with a ten mil pad and when I said, remember I said like, do your finish hole size plus ten for the pad, this only gave the hole size plus four, and it wasn't enough to make sure that people wouldn't totally drill you know, have too much because of misregistration material movement.
Every time you add a process, you add misregistration. Nobody in Asia would take this business, and we actually had to help the customer convert the whole design to another via structure type to be able to pull it off. And the way this happens is one of two things: if you're a major customer and you go to a, you know like a smaller shop, they are going to be so hungry for your business they're not going to say, no, no, no - we can't do that. They are going to babysit every single panel and put them in the drill machine by hand and make darn sure that they're going to get that for you.
Or there are probably a few select super, super advanced shops that are just doing onesie-twosie jobs and they can meet these kind of requirements, and these tight process tolerances, using direct imaging everywhere you know, using single headed drills for the production panel rather than five or six spindles that we use. And so it's not even saying that that particular circuit board fabricator was a bad designer - it's just that they're only designing for their site capabilities and probably pushing technology to make a big customer happy.
Right, and that may be their niche, that may be their niche market - but again they're not thinking particularly ahead, they're trying to help their customer be - - so it's kind of myopia. They're just designing for that, and they're great shops, they're great shops very, very capable, but not unless you tell them up front or you start this conversation up front it can go bad like that. On a consumer product that, okay it's August let's go into production and then wait, stop. Stop everything and the cost, the headache to that customer, they have to respin the board, run the protos over again and do all the testing over again. And now, schedules are lost, time to market is lost, you know so that it can become really painful very quickly and very costly.
Yeah very costly.
And I had another similar design that my customer had a design with 5 mil mechanical drills and 9 mil pads and most shops I know don't really drill mechanical 5 mils. So that was a tough one for him to go into production. So that's a real common example. The wrong size drill with the wrong size pad, or one that I just saw recently, was a really thick dielectric that still needed a blind hole and it was planned on being a laser hole because they wanted some big RF circuits on the outer layer. Which means they needed a thick dielectric and normally if you're using laser micro vias you have very thin dielectrics. And I was able to confirm that we can do it over in China but it's - it wouldn't have been my first choice for a design you know, and it kind of set me back but - but we were capable on that one.
Yeah so, you have a saying that I like which is: pick your experts wisely. So tell us what that means? What you mean when you say that; pick your experts wisely?
Well if you're going to listen to an expert, they're going to segue you to the path that they know, and if you pick the wrong expert and they take you down a garden path that nobody else can fabricate. I know that there are shops that they'll say: let's do this and let's have the customer design it this way because then they can't go anywhere else. It's a way to guarantee their business.
I can confirm that you know, I've seen entirely that. It locks you into that job.
It locks you into that job, and you know, I can see both sides. I'm like this ambidextrous Gemini so I can see both sides of the story. I can see an internal engineer wanting to secure future business for their location. But on the other hand, it may not be good long-term for the customer. And I'm in it for the long haul you know, I've been both sales and technical support, and a lot of times I have to work with customers to make slight modifications and design engineers; these are your babies. You don't want to have somebody coming in from the outside and saying, you know what, I really can't quite achieve that. Can we tweak your design a little bit? Who wants to hear that?
But if I have credibility, as somebody who's thinking for the customer, for the fabricator, and working towards the best solution long-term. I've - you develop trust, and you can get better work done. So, I choose to do the good path even though it probably means that I tell everybody I'm a conservative designer and so that means that if you design a stack up - if I design your stack up, give you the design rules, if you can meet them chances are one of my competitors can also do the work. Yeah, but on the other hand you know, the relationship most of the time means a lot.
Right it does, and not everybody has both the technical depth that you have, the integrity you have, and you have reached to top, top fabrication experts in the world. So that gives you a really broad perspective which I appreciate.
So Julie thank you so much. This has been so great, and I feel like we've just scraped the surface but I would like to invite our listeners, if you are available, to come to AltiumLive and Julie will dig into - she and Carl Schattke have an hour-long presentation plus QA and, will be introducing some new stack up and impedance tools in Altium Designer 19, and so they will be giving a really rich treatment of the subject of stack up. So if you want to hear more from Julie, come on out to AltiumLive, and we would love to have you. Thanks again Julie, it's always - I always learn from you every-
- - thank you.
Every time we talk.
So there is one other thing that we should talk about.
What should we talk about?
Okay the other background of seamless global transfer is that if you're working with a company that has multiple sites like DTM - we can take that - we can take the lessons learned from the prototypes, and transfer the data, and transfer the lessons learned over to the final fab site, so that it's not a new learning curve once it goes overseas. And that's a real advantage about really paying attention to this.
Right, which is a good point.
Yeah.
Do you transfer the learning curve along with just the data files right?
That's right yeah.
So good point. Okay, thanks for inserting that again. This has been Judy Warner with Altium's OnTrack podcast, and Julie Ellis of TTM.
We look forward to you joining us again next time. Until then, remember to always stay OnTrack.